well I have a 650 with Tmobile and no contract. So the question is to switch to a new company and upgrade to the 700p?

So, I would love to hear some comments from thoughs who went from the 650 to 700. Was it worth it and why? a better jump than the 600 to 700?
do o you still need Volume care? can you view PDF's? or do we have the same issue?
I think the most usefull upgrade in the 650 over the 600 was bluetooth. Does the 1.2 bluetooth make a difference? Can you play music over a bluetooth headset? or do you still need third party software(audigate)?

thanks for any thoughts I am a gadget freek at heart and will probably upgrade just for fun