There are a few competitors. I have now made a point of complaining about adultwork to WGs I meet. The issues with AW are extensive and only please AW. If only adult way weren't a spam thing but worked as it seemed, it would be a hit I reckon.
I think the smart thing is the other options, but to still put verification pictures up on them if you are Wg, and to stop the photoshop insanity. PS pics are useless.
I've been looking into all the alternatives to AW, as I'm annoyed with it. Not much point in being annoyed and doing nothing. Better to find the right alternative and suggest it.
I reckon if a site took off on here, it would have a good chance.