el cid,
You have a tough choice to make my friend.
There are some folders that may fit your needs but you haven't mentioned them in your post. One of them might be THE knife your looking for.

I've included a couple in my synopsis below. BTW, I have all the mentioned knives and have carried and used them all.
The Strider in ATS-34 is a tank of a folder but it needs a sheath. The bloody thing is nearly bomb proof in it's construction. A VERY large handful of folder. However, it is too thick to pocket carry for me and I normally carry a Sifu.
The Spyderco Chinook is an awesome folder(one of my all time faves) but it is tip down carry. In it's corner though is a CPM440V bowie style clip point blade

.
The heftiest lockback I've ever laid my hands on, it fairly screams at you to use it and use it hard. Sharpen 1/2" of the back edge at the tip and you have a formidable defensive blade capable of delivering a nasty back slash or tip rip. Also, one of the things I like about this knife is the fact that the ricasso is big enough to protect your index finger in the unlikely event the lock fails or to choke up on for finer cutting or slicing chores.
The AlMar SERE 2000 is a just plain all-out tough ass knife. It carrys well in the pocket and is the most comfortable to hold of all the knives you've mentioned. The VG-10 blade takes and holds a very keen edge. It is tip up carry with the clip mounted on the end of the handle for a low key carry. This folder is a real jack-of-all-trades and fills that bill very well.
The 710 in M2 high speed steel is one of my daily carry knives. It is "all that" IMO. A Tough as all Hell user, fairly comfy handle, one of the best locking systems on the market and an excellent hard working tool steel blade. It is also a tip up carry folder and the knife gives you the feeling that it is made to last for a life time. A hard act to follow for sure.
The REKAT Carnivour, while not one of your choices, may well be the folder your looking for.
Another "best lock on the market" Award candidate, your hand locks onto the handle and the knife feels like it was made for you. It is also tip up carry. You have a choice of either ATS-34 or D-2 for your blade steel. This is a totally GOOD thing.

The design was intended for self-defense but it works mucho grande in the utility roll too.
It is a very stout folder and gives you a great feeling of confidence in it's strength when you hold it.
I hope this helps.