I decided last year to finally replace my 20 year old classic SAK and spent a lot of time thinking about this question. I wanted a locking blade, since unlocked blades can be dangerous. I ended up picking the one handed trekker myself. It is not the UL option, but for an all around knife, it can be great choice.
The blade is long and very substantial, and the serrations on the end are in the right place, with the flat blade close in. The only thing I don't like about the knife is the chisel grind, which is upside down when I use my left hand.
I carry a knife mainly for survival and emergencies, so I do consider the saw essential. A SAK saw is very useful for cutting wood if you are building a fire. You can notch sticks otherwise too thick to break. In an emergency, a saw would also let you cut tough green wood sticks 1-2" thick for a splint or crutch or ski pole or to fix a snowshoe, etc. The longer the saw the better, and so the added length of the OHT makes the saw even more useful.
The locking flat blade screwdriver may not be needed hiking, but it is very substantial, and would be good for prying and leveraging. I agree that I don't need a bottle opener on the trail, but wouldn't rule out opening something back at the car.
I wanted a phillips since my ski bindings are phillips, and I can't rule out running into a screw on a stove or something. I also like having an awl, since there is really no other good way to punch a hole into something like tough nylon for a field repair of a pack strap, etc.
I have several multi tools that I like too, but I can't justify the weight of pliers unless I was fishing (or maybe skiing, still haven't decided that one yet). But for a SAK, the OHT is perfect for me.