I've spent the morning with a Fibracell 1 1/2 on an old Selmer scroll-shank C* soprano mouthpiece (on my Yanagisawa S901) and it plays SO easy and SO full on that close-tip piece. The Fibracells wear me out on my favorite open-tip pieces (SS-J, Morgan Vintage 6 and 7) plus they are way too hard for my chops when on the open pieces. But on the closed-tip pieces, it can come close to the power I can get out of my regular pieces and soft cane reeds and makes for a quick playing situation. No need to wet the reed, affix it to the piece, etc. I keep it on the mouthpiece and all I have to do is open my case, take out the horn, slap on the mouthpiece/Fibracell reed pre-set-up, and I'm ready to go.
Speaking of "lasting", the Fibracells last a long time. But when they go, they GO. I had one die on me mid-solo - it wasn't pretty. I always keep extras in my cases.
I always use a Fibracell on clarinet (besides not warping from drying out, they give me a solid, full tone and response from bottom to top - well, as far as I like to play up there). Not so with those Plasticovers (on any reed instrument I play) - but I'm repeating myself. DAVE