I've been running a Map Ecu for a couple years now. Only problem I've come across that really bothers me is when your RPM's drop below idle, it takes a little longer for the IACV to correct. My other friend running a Map Ecu has no problems what so ever though.
I made 340whp with it(ct26 57 trim), my friend made 389whp with one(boss to4e). I'd say if you are keeping it under 15-18psi, and 400-450whp, it's a good choice. Super easy to install/remove.
If you are aiming for more power, I'd suggest a standalone, so you can tune ignition timing.