I have tried Teavana's white lavender (I think they call it lavender dreams.)
It is awful. Just...awful. And I'm the sort that really likes florals.
I've been playing around with different brew temperatures, steep times, and leaf amounts but I have yet to find a combination that works well for me...but at $15 for 2 oz, you can be certain that I'm going to or die trying!
I don't think it's the lavender's fault, though. The white tea base isn't very good. The leaves are too processed. Many are very broken and the variable size doesn't really help matters. There are no full buds that I can find and very few fragments with the little 'hairs' like you'd find covering Silver Needle leaves or even Adagio's Snowbud. Moreover, all the leaves are tightly curled on themselves, like what you'd find in a medium-quality black. The water just can't get into the leaf with short steeps.