Like a few other's reviews I've read, I've also found that my first pair of long tights from you are fitting slightly bigger than my 6 pairs of shorts.
When measured up against the shorts, there doesn't seem to be any difference though. They do tend to slide down during training until I'm sweaty, then like all good Lycra, they stick!!
The other small gripe I have is that they are a bit short. I've seen other ladies in my club, who have the same issue, ankles sticking out. And we're not very tall either! Would it be possible to offer a standard length, as well as a slightly longer length? Say an extra 3-4 cm?