Anyone on the forum own one. I have a guide gun and just think those two inches make a big difference. (No comments ya sickos)

I don't own the STP, But I do own a 336 and a 336BL. The 336 has a 20 inch barrel and the 336BL has an 18 inch barrel.
Other than magazine capacity, I see no difference in accuracy between the two guns.
The 336BL does seem easier to handle and carry.