The S-2 is not a bad knife. In terms of strength, the integral lock is superior to the liner lock, but you get some disadvantages as well.
Let me first get to the good points. Quality and craftsmanship are very good. The blade doesn't wiggle, the lock is tight, the precision of the parts is above average. The size of handle and blade are good and the blade opens easily. The bead blasting of the blade is of the finer kind and shouldn't accelerate the rusting process too much. The hollow grind is high and makes for a sharp, pointy blade.
The weaker points are in the design of the knife.
Handle: It has too much curvature for my taste. The blade is always pointing down. I prefer knifes which you can put flat on a board.
Lock: As a result from the bend handle, the locking bar is curved too. In addition, the area with which it touches the blade when open, is fairly small. If you grab the knife harder, the locking bar will flex in under your grip and reflex out when you release your grip. This flexing is a vertical movement along the contact point with the blade, perpendicular to the pivot pin. It doesnt weaken the lock up, but gives you the strange sensation something is wrong with the lock. And it might rub some material from the bar with the time.
Cutout for the locking bar: This I would consider a design flaw. When you disengage the locking bar with your thumb by pushing it out of the way of the blade, then rotate the blade with your index finger, the bottom part of the blade will move through the thumb cutout in the scale. Since you have your thumb there while unlocking, you need to move the knife during this process to close the blade completely. This awkward procedure is the result of putting that cutout too far to the front of the handle. 1/4 farther back would have made more sense. My Sebenzas and MPFs dont have that problem.
All in all I have a love hate relationship with this knife. It has very nice features, good quality and a decent price. Too bad that the design quirks let it fall short of being an excellent product. On the other hand, there are not too many alternatives in that price range for integral locks yet.