From the comments here, it seems most rate their TRI-X about the same. I know Barnbaum also rates his at 160. In AA's book, The Negative, he also rates TRI-X at 160, FP4 at 64. I think Sexton rates T-MAX 100 at 50 to 64. Me, TRI-X is rated at 200, FP4 at 75, Pan F+ at 25, T-MAX 100 at 50.

It would seem that most rate their B&W films one stop slower then what the manufacturer recommends.

The variable for film speed is the exposure meter. I think the most popular is the Pentax Spot. Mine, a Soligor. With so many using almost the same equipment, it seems fitting most would have similiar ratings.

Film manufacturing is pretty consistent so just how much difference can there be, 1/2 stop at the most?

I do not own a densitometer, though sometimes I wish I did, and I may buy a cheap one in the future if I find a good deal. But great imagery does not start in the darkroom. Too much testing and experimenting can drive you nuts.

BTW, ordered more old emulsion TRI-X 4x5 on Tuesday from Calumet. They said they had about 100 boxes left.