pinballbrian, I picked up a collector-quality (really nice) Pro Football a few weeks back but have not set it up yet due to doing some necessary work to my basement gameroom.
I have played it before and it was one of the first wedgeheads I had ever played. While I could get the impression now two years into the hobby and meeting a lot of people and hearing their preferences that it wouldn't stand up to a lot of the more picky collectors that tend to have a smaller collection that consists of aim-skill/70's drop-target games like Jacks Open, Atlantis, El Dorado, and the like - I feel it is a very enjoyable game and does not throw any shame of what you would expect from a Gottlieb wedgehead of 1973, or even a few years later. It is definitely not as advanced or sequence-based as some wedgeheads but the uniqueness of the playfield and the great art package (usually the sports themes are very dull, somehow this one was as a major exception - I'm not even a football fan) makes it a great player for me and I am very happy to own one, especially in such nice condition. They didn't use to come up at all but over the last year or so I must have seen about 8 or so (which in pinball is A TON!) that have either been for sale somewhere in the world or games that people posted about just acquiring. Very interesting.
The lack of a shooter lane (the usual from the side all the way up to the top) on this game really shows how a game can take advantage of that extra space and you don't realize how much extra space the shooter lane takes up until you play Pro Football. The targets (lanes) way at the top are fun and it feels totally different while still having the Gottlieb feel to it. The four-flipper arrangement is also very fun, and shots are generally harder to hit as you can't cradle the ball or it'll roll right through the gaps.
I would definitely pick it up if I were you, especially if the price is right.