my two cents (i was able to catch a good chunk of their set):
fun to watch and quite amusing for about ten minutes. i can't say they aren't good at what they do, but what the scissor sisters do is probably what i like least of all musical genres. i consider myself open-minded and i can get down with everything from metal to country to hip-hop to noise to free jazz, but i really can't do disco, and that's what they do. i wouldn't even call it funk, unless your version of funk is more earth, wind, and fire than funkadelic/parliament and graham central station.
i also agree with the above assessments that the scissor sisters are largely influenced by late '70s disco and pop, especially the bee gees and elton john. i don't really hear much bowie in there, not even "scary monsters"-era. DEFINITELY not "low"-era.
i have absolutely no problem with flaming gay performances or flamboyancy, but if you're going to be that unabashedly "out," then i ask to be challenged or provoked in some way, whether it be comically or conceptually or musically. the scissor sisters failed on all three counts for me and came off like the musical equivalent of "queer eye for the straight guy," simply reinforcing stereotypes and cliches.
perhaps i'm just missing the boat, since they are supposed to be about a fun show, but that doesn't do much for me. i found them to be long on performance and short on substance.