I discovered a few little problems with TUIScrollView during my brief testing. First of all, when you are scrolling horizontally, it continues to use bounce scroll in the vertical direction while you scroll (so if your scrolling direction isn't perfectly horizontal, it will bounce upwards a bit and disrupt inertial scrolling). This also means that there is no bounce scroll in the horizontal direction. As mentioned in the title, I think it would be useful to have an option to disable bounce scroll as well.
I took a look at the code and messed around with it a bit to see if I could add horizontal bounce myself (I saw that some parts of the code dealing with horizontal bounce scroll had been commented out to be added at a later date) but was unable to get things working as well as I'd like :)
One more small thing to tweak may be the deceleration rate. The default value of 0.88 feels pretty good, but I can't help noticing that it feels different from [REDACTED]'s (not sure if its still under NDA...) inertial scrolling in that TwUI's implementation decelerates noticeably faster. I tried adjusting the decelerationRate property to match OS X, but it would always either decelerate too fast or too slow.