I have used the 4400 since its launch and continue to sell it to my customers. If I can offer yet another angle... When comparing the 4400 to the 720, I can say that from a warantee standpoint, the 720 is consistently sent back for repair and replacement whereas the 4400 is hardly ever sent out. Granted the improvements are vast in reguards to the newer 730 model, I am also sceptical. Go with the 4400, bro.

P.S. Be aware upon buying it that you have the software version in the phone is up-to-date. there was recently a batch of phones released with outdated software requireing them to be 'flashed' with the new version. the version # should read :TC4VZV08 and can be found under Phone Info.