Honestly? Most curved-back urban benches are fine for a quick 10 or 15 minute break, but once you pass the 30 minute mark, the flaws start to show up. That gentle curve looks inviting, and it can feel okay when you first sit down, but many of these benches are not really designed for long sitting sessions.
The main issue is lumbar support. A curved back often hits your mid-back or shoulder blades instead of supporting the natural inward curve of your lower spine. After a while, you either slide forward or hunch your shoulders, which makes your lower back ache. If the curve is too shallow, you do not get much support at all. If it is too deep, it can push your shoulders forward and make your posture worse.
The seat itself matters a lot too. Most urban benches are made from hard materials like metal, concrete, or wood slats. Hard surfaces create pressure points under your tailbone and the backs of your thighs. After 20 or 30 minutes, you start shifting around constantly because your body is telling you the surface is too unforgiving. In cold weather, metal and concrete also pull heat away from your body. In hot weather, they can get uncomfortably warm or sticky.
Another thing people overlook is the seat depth and slope. If the seat is too shallow, the front edge digs into your legs. If it is too deep, shorter people cannot sit back and use the backrest without their feet dangling. Some benches also have a slight forward slope to help rainwater drain off, which means you spend the whole time fighting gravity just to stay in place.
Armrests make a bigger difference than most people realize. A lot of curved-back benches have no armrests at all, or only have them at the very ends. Without armrests, you have nowhere to rest your arms, and you cannot easily shift your weight or push yourself up when you stand. Armrests also take pressure off your lower back by giving your upper body another point of support.
That said, not all curved benches are uncomfortable. Some newer urban designs use a deeper, more ergonomic contour that actually follows the natural shape of the spine. If the bench is made from wood or a composite material instead of cold metal or rough concrete, it tends to feel more forgiving. A bench with a slight recline, a deeper seat, and proper armrests can be comfortable enough for 45 minutes or even longer. The problem is that many city benches are built to be durable and low-maintenance first, with comfort as an afterthought.
So my honest take is this: if you plan to sit on a curved-back urban bench for more than 30 minutes, look for one with real lumbar support, a seat that is deep enough for your legs, and armrests. Wood or composite surfaces are usually better than metal or concrete. If you cannot find one like that, bring a cushion or expect to stand up and walk around every so often. Most curved-back urban benches are made for short rests, not long stays.