If you have an issue with service with ATT then, YES!
I had the iphone4 on ATT and had dropped calls and poor signal at home and work, so to me switching to Verizon was a no brainer...even though I had to pay 400+ to break 3 line contract.
My friend has the inspire and loves it, but if you can leave ATT without a huge fee for breaking contract, then yes I would switch
Note: I am Bias