People ask me why and it seems to boil down to this. Benchmade knives seem to put style before function, whereas Spyderco knives are made to fit the hand and do the job. Benchmade quality these days can only be described as mediocre. ZT quality is spectacular. Spyderco also is excellent.
In particular, I say shame on Benchmade for routinely shipping poorly sharpened knives. I cannot for the life of me understand why they would make such fine knives and then not sharpen them well -- and in many cases sharpen them sloppily or poorly.
The crown jewel of Benchmade knives is the axis lock, a very nice and solid mechanism. It they would just ditch the studs and start putting round holes to open their knives (not to mention sharpen them, did I mention the fact they often do a terrible job sharpening their knives) they would really have something.
My all time favorite Benchmade is one of their least expensive - the Griptillian. Get the version with the hole.
I am also fond of the Loco. It is a big husky knive.
Other Benchmade knifes that are special are the 940, which many say is the best knife Benchmade has ever made, and the Contego aka the 810. I like the Contego. It is a big knife, uses M4 steel, and unlike many other stud knives, the stud works naturally.
The first high quality knife I ever owned is one they no longer make, the AFCK. The AFCK has a sort of cult following and they try to make enough noise to get Benchmade to bring it back. I'm not sure where I stand on all of that. I like the knife, but for sentimental reasons. I think there are many much better designs these days.
Tom's Knife Info / tom@mmto.org