[mikedomi]

the only con that we have come across
is when you are in a small room and you have to put the singer right up on the tower you get some feed back

they say you should be at least 6 feet from them for best result
put some time that is not possible

there is a whole list of pros

I would strongly suggest a mixer a good one the Bose are nice
but a good eq is necessary for rooms that aren't so sound friendly

the vocal just jump out at you I have never had a speaker that the vocal were so strong on
go to bose.com and check out the forum for this product
there is a wealth of feed back from dj/kj there in there forum