I love both pistols but I only own one of them, a MKIII 4. I use CCI Mini Mags and Federal High Velocity ammo and have no problems with either. Disassembly without a problem is no further away than the nearest of many YouTube videos documenting the process. Buy either one and you'll be happy you did. I'm partial to Rugers and own an LC9, an LCR in .22 and an SR22 in addition to the MKIII 4. Good luck with your selection.