I've used both a iPAQ 6315 with IP Blue/SCCP (802.11b) and and a newer Sprint HTC Touch (EVDO) WM6.1 with Skype. Neither had good call quality with VoIP. I do use Skype on my PC all the time with no issues. Not sure if these phone's don't have enough memory, cpu, etc. In either case the battery drained down much faster using these VoIP applications. They were neat to demo but didn't have a real purpose.
I would stick with the CP-7921 phone and Cisco APs if you need wireless VoIP, conference, transfer, etc.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...