Well, in real life this depends.
If the HP numbers are perfectly equal then you'll only get better acceleration with AWD if your tires are slipping with RWD (keep in mind the RWD vehicle is lighter too). AWD will be better in adverse conditions due to the increased traction. If traction is maintained though, the lighter RWD vehicle with the same HP should theoretically have better acceleration (simply due to weight difference alone).
Personally I'd go AWD every time because roads aren't all perfect and it's not sunny here all the time.