Crap, plain and simple.
The blade designs are pathetic, they don't work for 99% of the cutting you might do, the serrations are next to impossible to resharpen, the steel is run of the mill Chinese junk (they're made in China after all) for ten times the cost of run of the mill Chinese junk, the grips are impossible to use comfortably, they don't fit ANY human hand, the finger grooves are either too large to use or too small or just ridiculously shaped etc etc etc.
The absolute best Spyderco knife I ever held in my hand was a $5 Maxam clone. Same Chinese factory, same grip and material, same blade and material etc etc etc. The thing that made it better than a crap Spyderco was that it was $5 crap and made no bones about it. It's still crap, but at least it's not ridiculously overpriced crap.
Addendum to Pierre: I have the same exact knife in my hand right now. From the bottom working up....
The grip has the tapered palm swell part at the bottom and then the single wide "finger groove" just below the blade pivot screw. Sort of like a long, narrow pistol grip. The tapered/swell part *should* fit back along the center of your palm in a rapier-type grip....it doesn't. It's too wide to fit the hand. The "finger groove" just above it is then too wide for one finger but also too narrow for two....so you end up holding the taper/swell pommel area in your palm with the last inch and a half of grip sticking up out of your hand. The clip on the back is then digging into your palm and the entire grip is uncomfortable. It's a piss-poor design that started life as some freak's fantasy crap that a lot of folks bought into and choose to believe it's some terrific design that they lucked into finding but just haven't mastered yet.
Basically, it's a crap design that a lot of folks keep telling themselves is good. No one wants to admit it sucks and that they fell for it.
The *ONLY* comfortable grip on that knife is to hold the grip sideways, your thumb on the flat middle of the blade, your two middle fingers wrapped around the finger groove like you were using it to clean your fingernails. Sorta defeats the $40 "police" knife concept, eh?
The serrated blade, yes, there are triangular stones designed to sharpen serrated blades on these things. The Lansky one I mentioned is a good example. I bought it just for that. It only fits the wide serrations, though, not the small ones. To sharpen the small ones, you would end up grinding them wider and wider til you had all wide serrations. Serrations are only on one side of the blade, too....and to use that triangle stone on them, you end up pushing what's called a "wire edge" over to the flat blade face. To remove it there, you have to use a flat stone....which in effect sharpens away the serrations. Serrations are thus impossible to resharpen. Yes, you can hone them once or twice....you can't resharpen them. When that blade was originally made, one face was ground first, the one with the serrations. That entire side got ground, the serrations cut, then the blade flipped over and the back edge ground off. It's the back edge grind that originally sharpens the serrations....but you can't do it because it grinds the serrations away. It's a catch 22 sort of thing. The only thing you're left doing is using the knife til the serrations go dull and then stoning a straight edge onto the blade which loses a lot of steel.
Blades are designed for a specific purpose. Over the thousands of years mankind has used knives, certain basic, "classic" designs have evolved and lasted. You have a two edged pointed dagger....a classic fighting knife. Narrow grip that fits sideways in the hand like a rapier. Thousands of years old. In fact, several found in Tut's tomb could be mistaken for modern fighting knives...same exact design. Hunting knives....what most folks today term "bowie knives". Single edged heavy blade with a curved tip. Used to do everything from clear brush to skin animals. Thousands of years old, too. A "skinning knife". Self explanatory. Small to medium knife with a curved edge. Even such modern stuff as a "pen knife" has a specific use intended in its design.
Look at your Spyderco and see if you can figure out what it's designed for? Fighting? Nope. Very poor fighting design. Skinning? Hunting? Opening letters and packages? Maybe. Fact is, it makes a very poor *anything* blade. It's fantasy crap passed off as a serious knife.
The closest historic design to that Spyderco blade is an old Norse scramsax blade....but the sax was designed with a straight grip that allowed choking up close on the blade for detail work. The Spyderco doesn't because the grip, again, sucks rocks.
The only Spyderco knife I still currently own/use, I removed the blade from the plastic grip and welded the blade to a half inch diam steel rod with an inch brass ball on the end. I use it for carving fine details in my staves and canes.
Steel....it's common China steel. Not bad, but not top of the line. I've seen far worse many times. (Gerber is the same) Any other China knife made from the same costs $5, not $50, though. So if you're paying $5 for a cheapo Chinese Maxam identical to the Spyderco and the Spyderco is being made by the same folks as the Maxam....where do you figure the extra $45 is going when you buy that Spyderco? Gold foil lining inside the handle where you can't see?
Here's a tip....by paying more for an item, you aren't making that item any better. You're just padding someone's pocket along the way.
If you insist on buying Spyderco crap, I'd suggest you buy that cheapo Maxam clone for $5 off of Ebay and try it out first. Once you have, you'll probably never buy another Spyderco. Spyderco's market consists of about 49% cops and wannabes who think the name makes it good....and about 49% teenagers who think "if the cops buy this crap, it has to be good".
Sorry for the length. It's a topic I've talked on lots of times these past years. Always gets me going.