you can't compare different dynos. My 325i with pbx put down 195ish hp on a dynapack, and later with the 3-stage IM and AA software, it put down 236 on the dynapack dyno.
stock, on a dynojet, my car was around 179whp. My friends E46 330i ZHP with performance exhaust made 185 to the wheels on a dynojet dyno.
it's more important to compare your before and after runs on the SAME dyno, as even dynos of the same brand can show variations. So while your dyno may be accurate from run to run, you still can not compare it to any other dyno unless you test them with the same car in the same conditions to see what the differential is.