Haven't tried Mama Melrose but ate a Tutto's a few weeks ago and LOVED it. From what I've heard about MM, the food at Tutto's seems to be a little fancier and it was excellent.
We used our DDP credits there so they do accept it.
I've eaten at both recently (well...in the past year) and I'd say Tutto hands down. MM is decent but it's more like an Olive Garden/Macaroni Grill. Tutto is definitely authentic Italian food. Tutto is def on my MUST list every time now.
Mama's is good theme park dining. Tuto is a cut above that. If your theme park plan lines up better with either restaurant, let that be the deciding factor. If you are flexible with park choice and dinner location, Tuto would be my choice.