I think the 338-06 is a fine cartridge, Not much you can't do with a 210 Partition at 2750-2800fps.
Although I have one, I would never argue that it is popular. Since I got on a 338 Fed kick, and have experienced it first hand on a wide range of critters, I don't see the need for the 338-06.
Back on the Sierra 215 GK, I was told by multiple sources that it is essentially a 250 GK with the tip trimmed back. The jacket at the tip is very thick.
