They are very different knives. While neither is what I'd call a masterful utility knife, the Kabar comes closer than the SOG. The Kabar has significantly more belly in its edge and a larger handle. They're both saber ground, and while the SOG is saber-hollow and the Kabar is saber-flat, the SOG's stock thickness is so much greater than the Kabar's that its edge is still thicker in spite of the grind, and then rapidly thickens as it moves towards the blade flats. This extreme grind really limits its cutting capabilities. It can be made very sharp, of course, and shave arm hair and make shallow cuts all day, but when cutting more deeply into mediums where the whole width of the blade is inside the cut, the effort it'll take to pull through the rest of the cut will increase hugely.
So, not as good a utility knife. But---it was never meant as one! It is a fighter, and in that regard it easily (in my opinion) surpasses the Kabar, as it has a much more effective piercing point, better guard, more neutral balance (although heavier) and--in my hand--a much more easily indexing grip. It's stronger than the Kabar due to the much thicker stock, and the point is more easily guided in a stab than the steep up-sweep that a Kabar has.
So, you just have to decide what you want. What makes them classic is that they're old designs, and you can buy one and have something just like (or very similar to) what G.I.s, Marines, Spec-Ops etc. have carried into combat. The other point of comparison is, obviously, price. The fit and finish on the SOG is much higher, and all the examples I've seen have had extremely clean and even grinds. The Kabar is still what it was originally created to be: a reasonably inexpensive "jack of all trades, master of none" tool, and perhaps won't make you wince as much when you get that first big scratch in it. Of course, once scratched, you'll be able to enjoy either of them significantly more.
So yes, some features in common, some not so much. You can cut with a SOG, and you can fight with a Kabar. If you like it, get it--life's too short.