I ordered the Repetto tights from the Freemotion site in April and I was still waiting for them in late November, when I wrote Freemotion and instructed them to send me their Major Motion tights instead.  These came very promptly.

I twice received the Mirella tights from tutu.com, and both of them were defective - the gusset tore out almost immediately.  (The second time this happened, I was going to wear the tights for a performance, and I was backstage warming up.  Fortunately, I had M. Stevens tights in my bag, so the day was saved.)

Tutu.com informed me that I was the only person who had made this complaint, yet their website now refers to Mirella tights as "improved and reinforced," so I can't have been the only one who received lemons.  I returned the second pair in September and at that time asked for the M. Stevens footless instead.  But tutu.com did not respond to that request, or any of my subsequent emails.

I've had good experience with NYDancestore.com and Sansha.  Sansha tights have shoulder straps, which is just what I wanted, since I have trouble keeping tights up even with an external belt.  One possible drawback to Sansha tights is that they are very, very tight indeed.  The first 2-3 times, I had trouble getting them on, the footed ones especially.  You have to be very careful about properly positioning your feet once you get them past the knee, because beginning at the upper calf each tights leg gets very narrow and it's extremely difficult to make adjustments after that.  Also, even though now it's easier to put them on, it's still not so easy to take them off.  They are so form-fitting that after class it's like all my sweat has welded the tights to my body.  Still, they are well-made and durable and very comfortable, plus I have complete freedom of movement.

I also want to recommend WearMoi, which is a company in the UK.  Their tights are very comfortable and their dancebelts are the best on the planet.  WearMoi's products are a bit on the pricey side, especially when you factor in shipping and handling costs.  Also, although they have generic sizes, if you want something customized you must be certain to make the proper conversion from inches to centimeters.  See http://5zencatalog.com/WearMoi/Mens_Dancewear.html