Mixed here on the 150/150. Mine was a Bush/Williams/Avcon and DID NOT have the GW increase (a piece of paper that ACT does have and will sell for about $1200...no other changes).
However, as mentioned many times before....many 150/150's without the STC routinely fly at the ACT GW level without consequence with the possible exception of questionable insurance applications.
Having said that....if you like a 182 or 172...you would LOVE a 150/150 for single or double pilot short/hot/high operations. I know from experience.
