I honestly haven't come up with a good comp yet. Uggla had far more power than I expect from Shaw but also likely had a considerably worse hit tool. I thought about Pedroia but Pedroia is likely a significantly better defender and, though I expect Shaw to have a higher BB%, he'll also probably have near double Pedroia's K%. Michael Young had a better hit tool, but I expect Shaw to have more pop and be a bigger threat on the bases. I come back to a guy like Rickie Weeks, but with less swing and miss and better defense. A guy who could possibly give you 20/20 in his best years and you're maybe looking at .270/.280 batting average and .350 obp. A guy, like you said, in the 3-4 WAR range most years with peak years a bit higher if things go right.