There are a number of photoetched track sets for 1/72 Tanks. I have a couple of Unimodel 1/72 kits, which already come with plastic link length tracks, which look pretty good. Could I get even better results with aftermarket photoetched tracks?

IT Depends on how much "work" you want to put into it.
I bought the ACE BMD and ended uo throwing away the PE Tracks after three tries.
Since this was "supposed" to be a fun build, and not for showing off, I sacrificed an ESCI M113 for it's tracks.