Sora vs Mizu: Pocket Spring Mattress — Medium Firmness or High Firmness?
Partilhar
Sora and Mizu are the two pocket spring mattresses with the best value for money in the Dreamura range. They have a similar structure — but different firmness levels: Sora is medium firmness, Mizu is high. This guide explains who each one is for.
If you have reached this page, you have probably already decided two things: you want a spring mattress (not pure foam) and you want something that will last 10+ years without losing structure. Good — that is the most important decision. All that remains is to calibrate the right firmness.
Contents
- Common structure, different behaviours
- Sora in detail
- Mizu in detail
- Why firmness matters (and what many people confuse)
- Which one for which profile
- Specifications side by side
- Frequently asked questions
- Final recommendation
1. Common structure, different behaviours
Sora and Mizu share the same structural family:
- A core of individually pocketed springs (each spring in a textile pocket that isolates movement)
- Upper layers of HR (high resilience) foam
- No memory foam (excellent for anyone who dislikes the "hug" of memory foam and prefers a more classic feel)
- High ventilation (you can sleep 8 hours without overheating)
The difference lies in the springs — the Sora carries Mitsunowa springs with three support zones — and in the density of the upper HR layer. Together, this translates into two clearly distinct firmness levels.
2. Sora in detail
Firmness: Medium.
Height: 20 cm.
Feel on lying down: Balanced. The body settles in, then finds stabilised support. You feel the springs responding by zone — the shoulder zone gives more than the lumbar zone.
Ideal for: Those who sleep mainly on their side, do not want excessive firmness and prefer more immediate comfort.
How the Sora behaves in practice
- Side sleeping: The shoulders and hips sink in just enough to keep the spine aligned. No pressure points.
- Back sleeping: Good lumbar support but with a soft feel at the shoulders and glutes.
- Stomach sleeping: Marginal. Medium firmness may allow slight sinking of the pelvis — anyone who sleeps in this position should try it first or choose the Mizu.
- Couples: Excellent. The pocket springs absorb movement. You can move without waking the person beside you.
See the full specification: Sora Mattress.
3. Mizu in detail
Firmness: High.
Height: 23 cm.
Feel on lying down: Traditional. The body does not settle in — it is supported on top. Anyone who grew up with old school spring mattresses recognises it immediately.
Ideal for: Those who prefer the traditional firm feel, sleep on their stomach or back, and value ventilation.
How the Mizu behaves in practice
- Back sleeping: Spine aligned. Lower back well supported, with no sinking.
- Stomach sleeping: A good option (this position requires a firm mattress so as not to misalign the spine).
- Side sleeping: Functional but not ideal. There may be pressure at the shoulders, especially with broad shoulders. This can be mitigated with a high, firm pillow such as the Kaiteki or the Nobi.
- Medium-high weight: A good choice. The Mizu is firm and does not give way. For even higher weights, the Samurai offers more support.
- Warm climates: Cooling. For anyone who gets warm at night, the Mizu is one of the best Dreamura choices.
See the full specification: Mizu Mattress.
4. Why firmness matters (and what many people confuse)
In mattresses, "firmness" is the feel on lying down. "Support" is how well the spine stays aligned. The two are not synonymous — and the confusion leads to wrong choices.
- Very soft mattresses can have poor support (the spine drops in the middle).
- Very firm mattresses can have good support but poor comfort at pressure points (shoulders, hips).
- The Sora balances both for average profiles.
- The Mizu prioritises support and ventilation.
The general rule: heavier, sleeps on the back or stomach, prefers the traditional feel → high firmness. Lighter, sleeps on the side, likes a balanced feel → medium firmness.
5. Which one for which profile
| Profile | Recommendation |
|---|---|
| Medium-low weight, side sleeper | Sora |
| Medium weight, side sleeper | Sora |
| Medium weight, back sleeper | Technical tie |
| Medium-high weight, back sleeper | Mizu |
| High weight | Mizu (or Samurai, for even more firmness) |
| Stomach sleeper | Mizu |
| Gets very warm at night | Mizu (the better ventilated of the two) |
| Couples with different weights | Mizu (does not give way on the heavier side) |
| Couples with similar weights | Sora |
| First home, first quality mattress | Sora (more immediate sense of comfort) |
| Those who had spring mattresses and liked them | Mizu (continuity of feel) |
| Those who had memory foam and disliked the heat | Mizu |
6. Specifications side by side
| Criterion | Sora | Mizu |
|---|---|---|
| Structure | Mitsunowa pocket springs, 3 zones + high resilience | Pocket springs + high resilience |
| Firmness | Medium | High |
| Height | 20 cm | 23 cm |
| Ventilation | High | High |
| Feel | Stable, with adaptation at the shoulder and hip | Firm and ventilated, without sinking |
| Memory foam? | No | No |
| Ideal position | Side, mixed | Back, stomach, mixed |
| Sizes | From 190x90 to 200x180 | From 190x90 to 200x180 |
| 100-night trial | Yes | Yes |
| Warranty | 10 years | 10 years |
| Price from | 309 € | 329 € |
7. Frequently asked questions
Can I try both before deciding?
Yes. Both mattresses are in the Dreamura showroom in Algés (Av. das Túlipas 23). We recommend lying down for 10-15 minutes on each in your usual position. The difference is felt within seconds. And at home you have 100 nights of trial, with free collection.
Will the Sora feel too soft for someone used to traditional mattresses?
No. The Sora is medium firmness, not soft. Compared with commercial "medium" mattresses, it is slightly firmer than the Portuguese average. It does not have the "sinking" feel of memory foam.
Is the Mizu too firm for me if I liked the Sora?
Probably yes. If the Sora feels balanced to you, the Mizu will feel harder. The difference is noticeable. If you like the Sora, stay with the Sora.
Can I add a topper to the Mizu to make it softer?
Yes. The Shizuka Mattress Topper adds 5-6 cm of softness without compromising the core support. A good solution if you like the Mizu structure but want a little more surface comfort.
Which of the two better supports a higher weight?
The Mizu. It is the firmer of the two and does not give way with use. The Sora adapts better to medium-low weights. For even higher weights, the Samurai offers more support than either of them.
Do these mattresses work on an adjustable bed base?
Not recommended. Spring mattresses do not adapt well to adjustable bed bases (electric mechanism). For adjustable bases use foam mattresses such as the Hisui or the Kaizen.
Which lasts longer?
Neither lasts measurably longer than the other: both have a 10-year warranty, covering manufacturing defects and loss of support. Both can be rotated and flipped, which is what most extends the life of a mattress. Choose on firmness, not on durability.
8. Final recommendation
The choice comes down to:
- Sora if you sleep on your side, are of medium-low weight, prefer a balanced feel and do not want strong firmness.
- Mizu if you sleep on your back or stomach, are of medium-high weight, prefer the traditional firm feel or get very warm at night.
For couples with different profiles, both work well — but the deciding criterion is the heavier sleeper. If one is considerably heavier than the other, choose the Mizu.
If in doubt, speak with Sleep Advisor Ana Cristina — +351 21 150 95 04. No pressure, no script. She asks 5 well-chosen questions and points to what makes most sense.
See also
- How to Choose the Ideal Mattress — 2026 Guide
- Takumi vs Mizu vs Sora — Three-Way Comparison
- Hisui vs Samurai — Severe Lower Back Pain
Explore: Pocket spring mattresses · Sora · Mizu
