If you can't afford a Sebenza the Benchmade Pinnacle uses the same lock. Mission Knife and Tool (www.missionknives.com I think) also has a folder with this sort of "integral lock", it's a sort of "mutant linerlock on steroids".
Properly done, a lockback can be strong but it won't be smooth - a clean reliable draw is critical for "combat grade folders".
Take a look at this thread and you'll see what we mean by lock failures:
and a followup:
One more thing: I personally favor BIG folders, up in the 5" or even 6" class. Spyderco and REKAT are in the early design stages of making such "megafolders" based on the REKAT "Rolling Lock" - which is as good as the Sebenza Integral, BM Axis and others mentioned. A 5" advanced-lock knife from either company would be a DREAM.