I just bought this bike and after a 35 & 50 mile ride, I think I am really going to enjoy it. It's very light, so if you ride hills you will like that. For anyone interested, this article is one of the things that really tipped me towards this Slice:
http://aerogeeks.com/...-uitegra-di2-review/

This is a great price as the 3100 price was already a discounted price. Plus you would have to pay tax or shipping. Also looks like it comes with pedals. Good luck selling it.