I think the service life of a PL-259 is better. If I recall, type-n is only rated to be connected about 500 times.
7/16" DIN still PWNZ everything. In telcom, not much of anything uses type-n anymore, ATT's stuff is all DIN and most other carriers only legacy stuff use N.
As for LMR I think its crap in comparison to heliax. LMR leaks, a bird chews on it and soon water will intrude into your line. A certain wireless internet provider known for using WIMAX used alot of LMR400 and 600 and eventually I ended up ripping out almost every installation that used it. Why, it leaks, it crushes and it kinks. Sure heliax will kink too but not like LMR. Replaced with 1/2", LDF4-50 and not a problem since.
Actually there is nothing wrong with LMR for ham, I would definitely run LMR, if it was free. I rather pay a few more $$$ and run heliax.