Never noticed any speed decrease using 040 or 020, but my amiga (before it died) had a 040 powerpc card in it so most software was using 040 versions so i keep 040 in Winuae selected and they run very fast, i use the 040.lib what came with 3.5.
If your running WinUAE on a decent spec machine it should blow away the Apollo in terms of speed so oxypatcher and tools like that are not worth touching.
I recommend you get Amithlon it you want something that will make your apollo look slow.
