Glad to here your apex is working good,my buddie has one and he loves it except for the lack of any real top end.
I would think that these two machs you where running with, had 06 mapping installed,if that is the case I can believe you where all over them, and they fouled plugs and wouldn't start.
BUT, be very carfull about running a 05 with 05 mapping because your apex won't run with it if the guy has any clue.
This past monday my 05 mach-z with the 05 mapping and stock clutching ran 127.2 in 3000'
118.8 in 2000'
and 108.8 in 1000'
Not saying they all run this good, but don't judge them all by this one experiance.