I am on Verizon, I visited the store today to find out about my contract and when it ends, with the excitement of getting an iPhone this week. Unfortunately the ultimate decision was I need to stay on Verizon for at least 3 months, if not another year.
In the store, when I mentioned the iPhone, all of the Verizon reps had nasty things to say about it and said the LG Dare is SO much better. They were so persistent that they actually took me to a Dare and explained why it was better, feature by feature.
I walked out of the store thinking that the LG Dare was absolutely horrible. The Voyager is a much better phone with the Dare's touch screen being very awkward and the buttons being too close together which leads to accidentally hitting the wrong one.
However, they were very good at showing their Blackberrys off, without even trying, and I was almost sort of wanting the Blackberry 8830 by the end of the day. Plus, that plan is only $20 more per month for 3G equal speeds.
So, my advice is if you're looking for an iPhone-esque Verizon phone, check out the Voyager, the Dare isn't so great, and the Blackberrys are awesome. If you want the best phone, get the iPhone.