I use the Lauscha clear.
I have not had problems with it, except for a frit blend or two, and in that case, I blame the frit blend!
I tend to encase heavy and deep, so I love the no bubbles or scum.
I also encase over some DH's and SIS, and I haven't had a problem. I generally put them in the kiln hot. (not droopy, but still glowy)