I have them. They are better for feel than "regular" 35. It really, really hard to give a solid judgement though, because the bend and sweep are still a bit off of other bars I really like. But, they do feel better than normal 35s for vibration. I notice no control detriments at all, and I'm 225lb, so I definitely load a bike. I notice changes in handling from a 32 to a 34 to a 36mm fork, and I notice flex in alloy rims when I ride carbon rims. I flex a road bike handlebar and bottom bracket like crazy when giving it some juice. I don't notice "flex" in the OneUp bar over a 35, but I do notice harshness in regular 35s (which I know is flex in the OneUps, but not this "it's flexing" thing.)
No one notices detrimental flex for pumping stuff. That's a complete fat load of crap.
35mm bars are just stupid.