The LCI has never caused me any problems with thousands of rounds downrange. With the removal of the magazine disconnect, the Mark III is the equal of the Mark II.
I think that with removal of the mag disconnect AND removal of the LCI the MK III can get close to the MK II, but just because you've not had problems with the LCI, many, many others have. Including AD's, and the pistol malfunctioning especially when getting a bit dirty.
The other issue with the MK III is the placement of the mag release. There was nothing wrong with the heal release on the MK I, and MK II. These are target, and plinking pistols with no reason for "tactical" magazine changes. The placement of the mag release to the frame, while maybe a nice marketing move, does nothing to improve the pistol.
The MK III incorporates needless changes which alter the pistol for the worse to meet ridiculous requirements from states like California. That is the only reason it was done by Ruger. They should have produced both MK II's, and III's side by side and sold the MK II in free states, and the MK III eleswhere.