The knives in question are two different animals.
The 73 will have better fit and finish, in my experience, and is a much smaller knife. None of mine have had any problems with blade play, although one (a Northfield Farmer) had the blade slightly touching the backspring. The pulls are about a 6 on the ones with a lanyard tube (never use lanyards on them) and a 7+ on the ones without a tube. They can be easily sharpened, but will not hold an edge as well as Queen's D2. I carry mine in the watchpocket of my jeans.
The Mountain Man I have came with horizontal blade play and the cutting edge was hitting the backspring, causing a deep dent in the blade's edge. Ten minutes of work took care of the play, but removing enough D2 to clear the backspring took ages. The work was worth it and resulted in a solid, hard working knife that is a pleasure to use (easily pinchable with gloves and a pull of about 5). If I feel the edge starting to dull, all it takes is a few swipes on my butcher's steel to bring it back to sharp. Never wait until the knife is dull to dress the edge. Mine carries unobtrusively in my back pocket next to my wallet with a short lanyard.
Both are great knives, albeit very different knives. Find examples to handle and then choose.