I noticed there has been reference to 9mm and 40S&W needing modifications in order to get the slide to lock when the mag empties. I have a full size steel .45 ACP and purchased a few additional mags. Two of these were purchased from CDNN and were listed for an EAA Witness and were 10 round mags.
I use these on a regular basis and I haven't had any issue with them not keeping the slide open on an empty magazine. The follower is a little higher than the IWI mags that came with the pistol, but they seem to work flawlessly.
Otherwise great information...