It all depends on if you want a machine with very little give-Neo, Rotaryworks,Blitz,Swiss made- or one with more give like the dragonfly,stigma,rapier. All these have give modeled after coil machines,I prefer that type as i like to also use my fkiron coil machines alot still. so its a no brainer for me. All thoe a no give short stroke rotary will work similer to a cutback shader in which you use scrubing motions for BnG. I have found a stealh with the short bearing works great for that style(ala joshua calrton-master of that style!)
So i think it depends on what style you like to do. I like big bold stuff so coils and rotarys that run like them work better for me. I have tried all the diff kinds on my wife and she says the rapiers and swashdrives hurt the least.
Just my thaughts thoe so find what works for you.