Tutto is a world better than Olive Garden. My Italian line up in WDW is as follows:
Tutto Italia
(Big Gap)
Tony's
(here is where I would put Olive Garden)
Mama Melrose
(Big Gap)
Via Napoli (pizza would rank a little higher).
We've been to Tutto Italia twice, and both times really enjoyed it. We did Via Napoli once, and the pizza was decent, but the rest of the food was terrible. My wife tried my chicken parm, and said "You like that?", as if no human actually could. The "spaghetti Torte" that came with it was completely inedible. It was probably the worse table service meal I've had in all my trips to WDW.