I love my 8125!! Honestly, I could stand for the processor to run faster... but, that's just something I have to wait for... And, it only affects me when I am watching video that I have not converted to the right screen size, or I am going to a graphically intense website while listening to MP3's via bluetooth.
Seriously, I can not imagine a better thumb QWERTY than the 8125. Each button is curved so they feel far apart and they have a good distict click to them when you press them...
I have not used the A630 to compare it... but, to anyone who wants a PDA phone... I would totally suggest an 8125.
The HTC Hermes is coming out in Europe, if it's not out already... It's the 8125 but better. I don't think it runs 850, though... if that matters to you.