I've seen similar posted here and there and about - but wanted to offer my observations as level-headed as I could:
1. TER (and yes others as well) is a great resource for hopefully finding what you want - do everyone a favor and post, post, post.  When you post, be descriptive.  Not looking for a novel - but if you used intel garnered from other posts then return the favor.  "I showed up, settled, then stuck my dick in her ass" isn't real helpful.
2. When a provider posts size you can usely lop 2+ inches off that number - providers - be real or be without repeats when your stated features don't measur to what you actually are;
3. I guess 3 seeming to be going standard.  Unless you getting a sliver of service (and that is what you want), then anything less 250 (?) is probably going to leave you bummed.  Anything above and beyond that benchmark will probably leave you bummed as well.
4. Do your homework - I've seen too many providers list under a slew different names - this should be a red flag in my book.  What are you hiding?  The fact that you don't measure up to what you advertised?  I was burned once - never again.
5. Hobbyists - relax on the "she didn't/wouldn't/couldn't" come - ask yourself the question if you could pop 10 times in one day.  Try asking - maybe if you're first in the door that day then its on the menu
6. "The pictures looked airbrushed/fake/etc" - again - do your research, look up the boards, google is your friend.  Most of the time the providers WILL look better in the photos.
7. Providers with no reviews - not sure what else can be said here.  If there are no reviews, clearly you'll be TOFTT.  If the provider has no reviews and no one on this board has intel then buyer beware.  Also - no recent reviews?  Hmmmm - makes me wonder as well.  Providers - encourage the hobbyist to post.  Consider searching for and connecting with an established hobbyist (they're not that hard to find) that will actually do a review.  It helps you out and it helps the rest out as well.  (Perhaps we need a Ebert and Roper of the hobby?)

Those are my thoughts.  Still learning, still trying to figure this game out.