Hiya,
Years ago I tried lots of OC types. Personally, I found the short tooth versions to have more of a bite than the long tooth razors.
The earlier Gillettes will usually have that Old Type head, and some newer models with the NEW Improved head could have the longer teeth. The teeth are slightly curved on the LT version, and they sorta stick out in the ST. That may account for the difference in the shave.
Martin