As somewhat stated above, a 68030 is the same as a 68020 except for the slight 256 byte data cache and the option for an on-chip MMU. As not so clear is the answer that the 1220 has memory that does NOT bother the PCMCIA port. For just plain gaming, the 68020 + on board RAM (ACA 1220) is fine. Jens has the release of the BigRam slated for this month, so I'm assuming the rest of his kit will be in the same time frame.
When computing power is really noticeable is in the 040/060 range especially with the PPC; add in OS 4.1 and you are living large.