I'm running Qt Extended Improved (based on 4.4.3, with bug fixes) and I'm
happy, I've been using QtE for the last 6 months or more and (with the echo
canceling fix and upgrading the Calypso firmware to moko9) it works nicely
as a phone.
I'm still running with a 2.6.24 kernel as that is very reliable for
suspend/resume, but I need to change it every other day with just
occasional calls.