I have the Treo 700wx (verizon) for work, and unfortunately we are still using a Microsoft Exchance Server that was put out on market in the last century so I don't have any push capabilites. I also have issues with the setup and functionality of the software on the phone, to me it is very clunky. It is windows based, but it just seems hard to use. the stylus funcion is nice too. But, I would prefer a HTC or Blackberry (see below)
I have the Iphone 3G (AT&T) for personal use and although it can now do Exchange Server it doesn't do me any good because my company's desire to live in a past century, and that I use MSN for my personal email. but since you are on Verizon, no sense telling you how much I like my I phone (except the cracks on it)
But I digress.
I would seriously look at the new HTC phones that are coming out on Verizon. I think the Diamond or the Touch are coming out soon. There is also the Blackberry series of phones they rock as well, and Blackberry is trying to become more mainstream with their software. Hopefully that helps. oh yea, it's a tank of a phone but the Verizon VX6800 is rock solid.
There are also some good websites that have Cell Phone reviews, one that I've looked at is phonearena