Pros: sign-up for hourly shuttle for MS which will get you the voucher for 2for1 buffet at MS, free voucher for $10 on big wheel, good rooms w/fridg, helpful staff, good breakfast buffet in Flanagans (go quite early to avoid the line,) clean pool, and handicap shower access in workout room.
The price is the lowest and I recommend you choose the internet rate to get that. We go to Misquamicut and hop on 95 to bring us right back to our room. On weekends, you can find several places that shuttle you and our hands down favorite now is Best Western Olympic in Groton.
We have tried many hotels in the Mohegan Sun area and found most to be satisfactory.