I have been looking for a tenoning jig for my table saw for some time. Now I see an old Delta 1172 for sale within ( but not real close ) driving distance from me. Newer General, Delta, Craftex etc. jigs seem to be constantly for sale in the $50.00 to $100.00 range; the older Delta 1172's only show up occasionally and usually in the $200.00 to $400.00 range. Before I go out and buy this one, I am just looking for opinions as to whether they are really worth the extra money.
I have one I bought about fifteen or twenty years ago, new. I paid less than $100 for it, so I doubt it's the version you are talking about. Heavy, but not as heavy as older ones I have seen. The weight is not an issue and I am glad it's not any heavier. What is a slight issue is "play" of "lash" in the threads. If you are adjusting it in one direction and decide to go back, it takes a significant turn of adjusting screws to get it to move. Perhaps the older usints are the same, but it would be nice if it were not true. The indicators and scales on mine are coarse and at best are a guestimate of where to start dialing it in.
I purchased a jig several years ago from either Rockler or Woodcraft in Indianapolis - can't remember the brand, as I recall it was in the $100 range new. I do remember it required quite a bit of rework to make it run true to the saw blade. Took me a few hours to modify it so the face of the jig was perfectly parallel to the blade. It has worked perfectly since then.
Adjustments are coarse, so does require setup and measuring with scrap, does hold fine after setting. Doubt there is much difference between brands, but maybe the older Delta's wouldn't require the rework I had to do to mine.