I too have had the experience of someone gushing over my fellow dancer in front of everyone and then saying "and you were ok too" to me but I think the worst insult I has was when I danced a piece I'd been working on a piece for 6 months, and a guy came up to me afterwards and said "just a piece of professional advice: I don't think you're ready to tackle a piece like that yet"
However on the very same night I was also told (by someone whose opinion I respect much more) it was one of my best performances ever!
The best compliment I got was actually last night when a lovely fellow dancer who I respect very much told me I was "so magnetic with a beautiful smile", which made me blush & beam at the same time
I think some people have an agenda to push, and others are genuine, it's just a case of filtering the genuine comments through.