As you say... apples and oranges.
Playing elderly materiel for the elderly crowd in a low volume, even distribution gig is as far away as you can get to providing contemporary music at contemporary volumes to today's clubbers, where the dance floor NEEDS to be several orders of magnitude louder than the rest of the venue. Or taking rock music to rock club levels.
As such, two completely different forms of PA are needed, both of which are totally unsuited for the other's job...
The problem here at SZ usually rises from one form of PA user assuming that ALL other jobs and situations are the same as what they are doing successfully with the form of PA best suited for it. Which, of course, is patently ridiculous. Strokes for folks... You can no more do a full dance floor gig with a Bose PAS at REAL dance floor levels, than you can a country club gig with a massive PA/DJ rig.
Some of you haven't been to a youngsters' night club for a while, have you?
Or been out to hear a rock band (or funk band, or 'emo' band, or...) or anything else much, lately. I can assure you, no PAS system (unless it is HUGE and unaffordable) can get even close to those volume levels (that the audience WANT
The PAS is an excellent system at doing ONE thing. Providing crystal clear sound at low to medium volume levels in mono with a very wide and even dispersion pattern. If you need this, it's your huckleberry... But if you need more conventional concert volumes, at CONTEMPORARY levels, it is, IMO, a very poor choice.
There is nothing wrong with this... nothing is the master of ALL trades. But I sure wish some of the PAS cheerleaders would recognize that there ARE situations where it is NOT the best choice, by a long shot. Many dance venues need the music to be it's loudest on the dance floor, and as quick a drop-off after that as possible. The PAS actually works against you in these situations.
I just wish we could quit 'evangelizing' these equipment purchases, and make a more realistic opinion about their strengths, and acknowledge what weaknesses they DO have. An unwillingness to admit ANY flaw simply comes off as 'fan'aticism...