I was scared to try it, but on the signature quilt I did this summer, it was really the best choice for the quilt. I was pleased with the way it turned out - I used the YLI monofiliment wonder thread. I did test a test piece and also tested how it stands up to being ironed - there were no problems with it.
Overall, I was pleased with the way it turned out, and would not hesitate to use it again if it was the best choice for a quilt.
Cheers, K
(I did blog about my experience with the thread)