" However, where square footage is a very precious commodity, paying the extra for MPPT may be the only way to go for getting the most energy from a panel set."
You can get a lot of muddled thinking along those lines unless you are careful. The basic assumption there is that you will need all you can get and you can get a certain amount.
The trouble with solar is that what you can get keeps changing so sometimes it will do more than you need and other times less than you need. This means there is no fixed amount you can count on and there will be (many--depending) times you can't get what you need.
It follows from that, IMO, that there is no point in spending a lot extra for a couple more amps, when a cloud can come by and steal your couple of amps anyway. The idea being that when you are not going to get what you need that day, it doesn't matter if you are second or third in the race, you are still a loser.
Since you are going to lose the race anyway, why spend extra for fancier running shoes?
Once you are behind, you have to catch up and then start over. Catching up next sunny day or two is problematic. Depends. Out comes the generator usually. So now the gen is out, who cares? It can do in an hour what solar can do all day.
Really, you just slap some solar up there and what you get is what you get. No point trying to squeeze every last AH out of it, while the weatherman is jerking you around all the time.
