@JoNty:
I tried DoomAttack and ADoom with my Falcon040/25 and ADoom was faster... DoomAttack seemed to be designed for 020 and 030...
If you have a graphic card the fastest Amiga 68k port I've tested was EDoom, a port based in ADoom but recompiled with GCC, it gave me 1fps more than ADoom when I switched to the A4040/25 / CV64 with P96...
BTW: Where are DoomAttack's sources?