I use Fireline and PowerPro almost exclusivly, although I am trying out the Stren Microfuse on one of my rigs. I'll post when I have enough experience with it.
The only real problem I have had with the fused and braided superlines is that they don't like to hold in planer board or downrigger releases. Considering that half of my fishing time is spent trolling Lk. Michigan, this is a real concern. My partner and I have found that securing the line to the release with a rubber band(use the ones sold for this purpose, not the ones in your desk drawer!)by half-hitching the band to the line and then clipping the rubber band in. the release works well. If you are pulling a large bait, it may take two bands.