For surrounds or rears, I wouldn't mind, but if these might be for your fronts, I'd say go with stands... I know a rear port 6" from a wall can get boomy... where mine are at right now, if I go 6"closer to the corner, I get a horrible mess (and that's with them being 18" from the wall!)!
Long story short, from a guy that's drilled into the wall: Be certain, then be careful! And if you do... Buy better brackets than you think you need!!!