My latest DM is terrific. There have been some glitches ("hey, boss, there's nothing in this store that looks like the POG I was assigned!" -- I was given the WRONG POG! Did what I could, got paid anyway). They do pay fast. I've only been with them a short time, but have had FOUR different DMs in that short time. Some glitches, yes -- growing pains, I think. The reporting is incredibly simple, compared to others. Narrative required only if something unusual happens; mostly y/n.
Like others, I hate dealing with WalMart. Waiting for a manager, check. Searching for the packages they were supposed to receive, check (OMG, 45 minutes in the back room with the manager, looking for a 12x18" bright green box!) (and you don't get paid for that, either, if you can't find the box at all, you don't get paid). I have to say, though, that all the WalMart employees I've had to deal with are gracious, helpful, polite, professional -- they just are clueless. Driving an hour to get there, spending 1.5 hours in the store, failing to complete the project because you can't find the materials shipped to the store, not getting paid because you didn't complete the job, check, check, and check.