Certainly both phones are modeled on the Sprint user interface (UI) overall, not the legacy Nextel UI.

I have not used a Qchat phone, so I can't say anything about the PTT UI's, but I do know for a fact that the overall UI of the ic902 is based on legacy Sprint UI, not the legacy Nextel UI.

The legacy Nextel UI's functionality and customizability is vastly superior to the legacy Sprint UI, at least for regular phone & PTT functions. Of course Nextel is punk on data & media, but for phone & PTT functions, including the "Smart Key" and other exterior buttons, the Profiles fuctionality, call filtering, etc, the legacy Nextel UI is waaaaaaaaaay better than anything from Sprint or ATT or VZ or T-Mo. That's one of the many reasons I absolutely refuse to switch over to Sprint's CDMA side at this time. I don't care if my cellular calls go out over CDMA or iDEN, but I do care about the functionality & customizability of the UI, and for my needs, Sprint-based UI offerings are nothing compared to legacy Nextel's.

For example, the exterior button functionality on my i560 allows me to make call-backs with ease without ever looking at my phone, even while I'm driving. As long as I can recall the order fo the last few calls I've made or received (shich is an easy thing to do), I don't even have to unholster my phone while driving. I simply press the "Smart Key" next to the antenna, press the volume rocker button to the appropriate number/order in the Recent Calls list, press the external speaker button (or the PTT button on my hands-free headset), and I've made the call. Never took my eyes off the road, always kept one hand on the steering wheel, never unholstered the phone. You just can't beat that simplicity, speed & efficiency, and only Nextel has it.

It's positively pathetic that the legacy Sprint executives still can't understand what makes a legacy Nextel subscriber tick.