Wackojack, on 2014-August-03, 06:59, said:
Many Acol players use a 2NT response as invite plus.
Seems like an overbid. I do not know any Acol players that are using this structure and have never seen it in the BBO Acol Club in the (many) years I have been visiting. More than that, is the information we get going to help us make a decision on going past 4♠ or not even if the auction remains uncomtested? And there has to be a decent chance of hearing some number of hearts or diamonds from LHO before partner gets to show us anything at all.
If we have a sequence that specifically shows a good distributional raise to game such as with Bergen then it is worth considering. But absent such special agerements the practical choice is 4♠.