Well, I scanned the entire thread, and could have missed it, but I see one use that no one else has mentioned the use I intend (that I could see).
Where I live there is NO repeater. There are also NO users active on GMRS. Why did I get it? Useful emergency comms with my family - what I consider an emergency - not what the FCC says one is. So, 3-4 licenses handle me and all of my adult kids who live 12 miles away (as the crow flies).
So, I've set up a parrot simplex repeater using one GMRS HT connected to an SR-112. This allows me to do a few things:
Map out the xmit/rcv locations on a map - how far I can reach, etc., etc.
Test various antenna mobile against various antenna at base - see what works best on what radio, and at what distance for MY area.
This test will occur at the same height/location that one would be holding the HT at my base
Test various setups and variations of what HT at the base seems to work best with what mobile HT - brand and model. (I suspect that brand-brand with same model probably works "best", but we'll see)
This isn't expensive, and if all HTs work "equally well", then they get handed out to the family.
I don't need to involve someone else who isn't all that interested, and will be THERE to answer (wife has a habit of doing "other things" for "just a minute", and 30 minutes later...)
Eventually, this could lead into more of a "proper" base station mobile, with antenna mounted on my roof, etc.
This is NOT a permanent repeater - just for my use for these purposes. I guess I could take it out with me traveling, and set it up somewhere to extend reach - but most likely I won't. It was a cheap setup to do testing and see what actually happens vs. theoretical what should happen. If it doesn't do what I think it should, then I can research that.
While there will be some variations in ground (different people, different ground), and the way that it is held - it should be more reflective than many other things I can think of. And most importantly - it COVERS THE AREA I INTED TO USE IT IN.
Sorry, if someone mentioned this earlier - but I missed it if they did.