>Actually, I do plan on using the SHIFT button or else I will need an extra 5 buttons >

Okay, they work a little differently but nothing that would make a whole lot of difference to you, from the sounds of it. Biggest difference - The I-PAC has a button which ALSO acts as the shift function. The KeyWiz has a totally separate button for accessing the shift function (less chance of accidental activation, one additional button on your panel), although you CAN wire the KeyWiz shift function to work SIMILAR to the I-PAC.
>Also impressed with the MACROS in the iPac.
Cool feature, Gets ZERO usage in MAME. Biggest usage for it is Emulators that want Alt-F4 to exit (but there are alternative or hacked version of most of these anyway). Also, note that you are limited to 4 macros per codeset, so this can't be used for PC games with 20 some Alt and 20 some Ctrl combinations - (not that you'd have that many buttons anyway).
>I do plan on using it for MAME only pretty much but my guidelines are:
>1) CHEAP
Hard to beat the GGG Eco2.
>2) EXPANDABLE
Neither one really from a hardware standpoint. Pretty much a draw here.
>3) RELIABLE
Pretty much a draw here as well. I've seen more problem posts with the I-PAC, but it's also been around a lot longer and has a larger user base, so that needs to be factored in.