I've used the Spydercard but not the SOG. The good and bad about the Spydercard: overall good construction, of course. Blade hole is well-positioned, big, and round. The very sharp point does come in handy. The downside is, when I started to work the knife a little harder, the handle isn't the most secure. The Spydercard is at the limit of my thickness and weight limits for this type of knife.
I have NOT handled the SOG, but theoretically, here are my predictions. The handle looks a bit more secure than the Spyderco's. The blade does not have a sharp point, a definite negative. The strange-shaped hole won't work as well as Spyderco's round one, I bet. So, up to now, mostly tradeoffs. The clip, which doesn't come off and apparently doesn't work well as a money clip, probably makes this knife beyond my carry tolerance for a knife in this class.
That's all theoretical. I'm still trying to actually handle one at a show.
Joe