For me I like D97 on my longbows,I don't use it for the extra speed I like it for the feel of the shot.On my Hill bow with dacron,when I add some wool yarn silencers I get handshock that will rattle your teeth.It's better with no silencers,but on my other Hill with ebony tip overlays I put on D97 and what a difference that made.And with a pair of whoolie wisps it is quieter then my Hill with dacron and has very little handshock if any at all.I use B50 on my older recurves but I like to spin up an endless loop for them.For some longbows you will get more handshock with dacron then with the newer materials.