Palm Treo 650 (CDMA)

I'm going to switch from a moto SLVR to a Treo 650. I'm curious if anyone finds anything really annoying about these devices (not about the device itself, but if there are some things on there you cannot change and it drives you nuts). I would love to be able to receive my emails, IM on the go, use the internet, etc. and I'm very close to just singing up today. Also, if I were to buy one outright, what would be an average price to pay for a good new one (anyone selling theirs - it would be for Sprint). One last question - anyone unhappy with their Sprint service and would suggest getting a Treo through Verizon or Cingular? Anything else I should be aware about? I know this is asking a lot of general questions, sorry - thanks for the he...
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