I like the new ambi safety on the MkIII. What I dislike is the new extractor design - I preferred the older Inglis-type extractor as the slide (IMHO) better supported the extractor making it less likely to skip off a rim when shooting sticky ammo.
The sights are an improvement over earlier guns, though the earlier ones can be upgraded. The finish is better, no biggie.
In terms of frame strength - a misnomer IMHO. The original forged frames were plenty strong anyhow. The slide, if anything, is what usually cracks. That being said, normal loads and appropriate lube will probably equal a slide that lasts almost forever.
Mint Inglis mags are the cat's ass, but many are totally worn out with bent feed lips. In such cases, a noew made magazine will usually make any old hi-power run like a champ.
If these were available in the double-action configuration (some have been made that way) they would be far more popular. A very solid design whose elements are copied today by just about every manufacturer.
I've had many Inglis guns and always end up with another after I sell one. Love these guns
