I had also heard good things about reefcleaners.org. As a result, I placed an order for 1,000 dwarf ceriths, 50 periwinkles, 10 fuzzy chitons, chaeto, and two nerites. My order qualified for free USPS overnight shipping. The order was trouble from day one. The order was supposed to ship numerous times but didn't. They didn't let me know when it actually shipped resulting in USPS not finding us at home. As such, the package sat an extra night at the post office.
The livestock inside was OK. Consistent with most other reviews I had read, I received way more than I ordered. I received about 2,000 dwarfs and 100 peris. The nerites were absolutely great. However, the ~2000 dwarf ceriths and 50 periwinkles eat the equivalent of one good astrea. 5 of the 10 chitons have died over the past couple months, the other 5 haven't done much of anything, and the chaeto was approximately one strand long. Overall, I was dissapointed w/my order. I expressed such to reefcleaners w/o the courtesy of any response.
Regardless of my experience, most people do have good success with them. I must have caught them on a bad day. However, if using them, then I would stick with buying the CUC critters common to our hobby like regular ceriths, astrea, trochus, nerites, etc and stay away from the "unique" stuff they sell like dwarfs, periwinkles, fuzzy chitons, etc. There is a reason they aren't common in our hobby.