The Stage One Maikonics conversion consisted of a modified AEi computer and also a modification to the top of the wastegate. Also included was a set of upgraded NGK sparkplugs.
There were two Stage One conversions available - one for the T1 and one for the T2...230BHP and 250 BHP respectively.
As Neil will no doubt echo, Stage One was the best bang for your buck, but there was a whole host of mods available in the Maikoncs literature that take them up to 440BHP, but the cost will escalate very quickly for smallish power gains.
Stage One is brilliant though with 250BHP and 320FT LB.
Maikonics converted cars are VERY rare nowadays...I think I'd be safe in saying that you could count the remaining number of cars on your two hands. Shame, as it's a wonderful piece of work that Simon did.