I'm coming from Verizon too, but I am in my first 30, so I should be OK.
They were all out of incredibles, so they sold me a droid and said I could return it when they were stocked. With my employee discount, the verizon 450+data is the same as sprint's everything data/450. They didn't have an evo display, but I checked the signal on a sprint hero, and the signal was 10db better, and the evdo download was >100kbps better. The girl at sprint promised they didn't have one of those repeater things in the store, and that wouldn't have impacted speedtest.net anyway.
I am totally torn between the 2 phones, but the signal difference near home, the pricing, and the difference in ETFs (vzw-$350, sprint-$200) are pushing me to the evo.
If it fits in my jeans pocket Friday, I'll go with it. I figure worst case, I have 30 days, and I can always change again if need be.