Forty-six more bucks than the other SPs, and in their profile picture that front sight looks like it's off of a rifle.
I definitely know now that if I ever bought one, it would be the original .22 SP. I like the simpler sights and six rounds better, just not the grip. Now that the new ones will maybe put OM prices down to reasonable, I could live with the crappy grip on a cheap enough OM.