Hey there!
The Cybex Mios truly is, in the first place, a gorgeous pushchair, so it's the perfect style choice if you do care about design a lot. I understand and support your choice in this way 100%. I am also quite a fan of its design - as well as a fan of functional pushchairs - and that's why I owned the Mios for a few months as well, actually right from my third baby's early months.
I'll start with the wheels. I found that the Mios's wheels are actually made better than the ones of its bigger brother Priam. They feature better, softer suspension, plus the rotating (as opposed to telescoping) handlebar means the center of gravity and overall maneuverability feel much better for me with this model. The push is super nice - even on uneven surfaces. Of course, you need to take into account that the wheel size means it's not an all-terrain jogger, and if you go into a hole bigger than the wheel itself, you can get stuck - but the curb popping, the bumps and holes tackling and all this were easy for me with the Mios. We did go through usual grass, gravels with not much of a problem, no rattling was involved either.
Seat-unit-wise, the mesh is great in the summer. We used it also in winter, so I can honestly say 'no worries' there. We did have the backrest insert, plus, think about it - the child is open on its front size, not touching the seat there (in any given pushchair), meaning you will anyway put winter clothes on it. The same goes for kids that also walk a little; they won't be protected at all times from all sides, either. With the right clothes, the insert, a footmuff, there's no way the child wouldn't be protected enough even in real cold. A good footmuff is a must-have (with any stroller in winter), so a Cybex one, or another good one (we owned the Lodger footmuff, and I heartily recommend it, so easy to use while being not that fluffy + super cozy), and the child is nice and warm in its pushchair. Again, I will mention the smaller wheels - they are not that good for deep snow, but in the city, if walking on cleaned pavements, there was no problem with the Mios (and deep snow is an enemy of any pushchair in general).
Comfort-wise, I found the Mios truly comfortable to use, and my son comfortable in it. The backrest is high, so I could put it in my older 4yo without problems, even if the seat seems narrower on the first look. If you don't need an all-terrain model, but you will appreciate something this stylish while functional, compact, and pretty lightweight, I can say go for it. Even the slight rocking I could do with the carrycot (yes, we did have it even wit a carrycot) was a pleasant surprise for me (for the size and weight of it). The only other special thing I recommend getting is maybe a sunshade - with the seat reclined, you may be needing that in the summer - but I found I needed one with any pushchair with a reversible seat in the hot summer weather.
