I really doubt I'll be using the state books often. I just think offshore has much more to offer. I am looking forward to taking advantage of any first deposit offers from the locals though. Being paid before leaving casino is nice too.
Like others have said, the more the merrier. Max out the bonuses and enjoy any promos. Otherwise, just line shop as usual.
I live in a state where it is legal and have money in FD and rarely use it, still use offshore. It's been weeks (and I place 15 bets a day) since I've found a better number on a game there (I check FD about 75% of the time, not every time mind you). Using rough math as a $200 game bettor, if I bet all of May's plays at FD instead of offshore, I estimate it would have cost me over $2,000 to do so.