Nothing wrong with the Spydercos. My first good knife was a 1st gen. Endura. My caustic sweat quickly spotted its Aus8 blade with a bit of rust when I worked out with it clipped on. Spyderco continues to be innovative with new lock designs, experimenting with new blade steels, and for really using a premium heat treat on all the steels they use. I think there has been a run of Enduras in ZDP-189 which is known for reaching high hardness and holding an edge forever--could be a bit fragile and chip in hard use. Knives like these allow knife nuts to try out new steels at much lower prices than custom offerings.
I don't really trust the lock back design--not necessarily because I use my knives hard but because I want them to be able to withstand a lot more than I can throw at them.
Spyderco full flat grind (FFG) knives, especially in some of their supersteel special editions, are renowned by knife nuts as great cutters/slicers esp. for production blades. They also have some really nice framelocks and linerlocks. I like the company a lot, but many of their designs don't float my boat because of ergos or the way that the clips are arranged. Ex. the framelock militaries are tip-down only while I prefer to carry tip up, etc.
-Chad