Another problem playing WHDLoad games on a 68000 CPU is the quit key for many games does not work, this is something to with how the slaves were coded.
If you did go for the ACA630 you can still play your old non WHDLoad games that don't support the upgraded CPU/Ram as there is a disable jumper and you can fit a switch to the jumper pins.
The ACA is a pretty serious upgrade for an A600 though, you could for example spend circa £70 on an A1200 and 4/8mb upgrade and play most of the WHDLoad catalogue of games including AGA.
Steve.
