Depends what you want to do with it. I had a treo 650 which was a pda with a phone tacked on. Now that's fine but i've come to realise that what i actually need is a communication device with some pda functions plus the ability to check documents (i loaded the treo with apps but besides splashid never used any of them).
the exc is a powerful beast and if you are familar with windows mobile is the way to go. It's got a nice big screen and the battery life is great - lots of 3rd party apps as well. However it's BIG and from all accounts is a pretty average as a phone.
I'm using a nokia e61 and even after only a hour or so of usage it's won me over. It uses s60 as it's os and as a palm man while i it's going to take some getting use to - i think it's pretty neat. The first two messages i sent via 3g (orange) but I am now connected via my wi-fi point. All done pretty with little fuss.