John Scifres makes a really good point that a backed bow can often significantly outperform a selfbow if made well.
With that said, performance can vary alot depending on design and bowyer skill. I have two hickory selfbows for example, one is 46# @26", and the other is 52# @26". They both shoot a 500gr arrow at the same 140-142ish FPS. The lighter one is a short recurve and the heavier one is a narrow bendy handle bow.
I also built a sinew backed ERC recurve, that consistently shoots over 150FPS @ 500gr and draws about the same 45#@26 as the hickory bow. Thats on par with my old York Thunderbolt of same weight. (All with FF string).
The point I'm getting at is that not all wood, or handmade bows are equal, and if you have any doubts, just chrono it, and see what energy it actually puts into the arrow. Thats what matters, not how hard it is to get to full draw.
I try to chrono all my bows, mainly because it helps the bowyer learn from minor design changes that might only result in a couple FPS, (i.e. efficiency) and can't be seen with the naked eye or felt with the hand.
and to second what Frank said, FF string is just like free FPS, which even the finest selbows can use. All my bows get FF. 8-12 strands of 8125, and padded loops. I don't pad the serving I just use the thicker serving material ... like .030 Halo maybe. Every bow will gain speed from FF, as long as you can resist making the string very thick with more strands than needed.