There is a reason that longbows and recurves are in different classes in tournaments, which is because recurve shooters generally turn in higher scores than longbow shooters. The same could be said of long target recurves compared with short hunting recurves. Or, straight-limbed Hill style longbows compared with reflex/deflex longbows with contoured grips. Of course, if a person works hard enough, and is talented enough, like Howard Hill, then he may quite possibly outshoot people in classes that normally turn in higher scores, because there is more difference among archers than there is among bows. Many people stay with a class of bows that might be considered more difficult to shoot simply because they like them better, for similar reasons that they chose archery over rifle shooting to start with.
But within a general category of bows, my experience is that you will find some bows that you will be able to shoot better than other bows. Other people will have different opinions, fortunately for the many fine bowyers out there. However, I think most everyone would agree that if you picked one good bow in a weight range that fit you and stuck with that bow, you would end up shooting better than if you tried a lot of bows looking for "nirvana," as you put it. But what's the fun in that?