I resisted signing up with MF for a long time--after reading many negative posts on this forum. I finally did, though, because I figured out they had the shops for a restaurant chain I was dying to shop. Nearly three years later, all I can say is, except for their low base pay on most jobs, I think they're a great company to work for. I've never had a shop rejected, and in a couple of cases where I submitted my report, then realized that something I wrote might seem contradictory or I hadn't known quite how to answer a question, I immediately wrote the help desk explaining the situation. In the first case, they replied that the shop had already been approved, so no worries. In the second, they wrote back, thanked me for the heads-up, and said they'd pass along the information to the shop editor. Shop was approved without issue. I think if you suspect there could be an issue with your shop, be proactive and alert them.
Also, I did two shops recently that required photos, and time/date stamps were on both. Not a problem.
The only thing for me is that I pretty much won't take any of their shops at base pay. Luckily, they must not have a lot of shoppers in my area, other than for the fast-casual joint. Lately I've been able to pick up some nicely bonused shops. Unluckily, those restaurant shops aren't being bonused as high as they once were, and I can't get them for what I used to.
But I still can get a bonus that makes it worth it to me. Every so often I'll do one at base so that they'll keep calling with the ones they "have" to have filled right away! Good thing, though, that overall I'm not doing as many of those, 'cuz my cholesterol sky-rocketed when I was doing one or two a week every week. Went way down when I cut back!
I learn something new every day, but not everyday!
I've learned to never trust spell-check or my phone's auto-fill feature.