Got the phone 2 days ago...like it thus far. Doesn't have every feature, but gets the job done for me...all I was looking for was something small, and with bluetooth...camera wasn't a big deal to me, but I'll take it.
A lot of people have complained that the Katana is flimsy, feels pretty solid to me, feels more solid then a RAZR IMO.
Only gripe I have is the lack of .wma and .mp3 ringtones, have to use .qcp (Qualcomm's doing). I added a bunch of ringtones, but they don't sound all that great, and they are low as hell in volume (a lot of people have complained about this).
As far as the service, Sprint>Nextel. Sounds odd since they are now basically one in the same, but the Sprint network is so much more stable then that of Nextel (maybe an issue of CDMA vs iDen?) I've gotten signal everywhere, get 2-3 bars in my basement where I was almost always without a signal on my Blackberry.
I d/l'ed Opera Mini on the phone and it's actually pretty quick...I'd say a little quicker then the internet was on my Blackberry.
Anyway, pretty pleased so far.