A Chef's Choice 310 is a fairly good sharpener.
Yes, there are other, better ways to sharpen a knife. But to go from just "other" to "other, better" you either have to spend significanlty more (like an Edge Pro) or be willing to master the skill sharpening on bench stones. While freehanding is not that difficult to learn a lot of people don't want to spend the time, or simply find it too intimidating.
Edgecraft, the company that designs and makes Chef's Choice machines solved most of the major problems that go along with home, electric sharpeners. If used properly they will not harm your knives, and they create a very durable edge with a degree of polish that's appropriate for the sorts of knives they usually see.
One of their shortcomings is that they are not adaptable. With one exception, they only sharpen to one of two particular profiles -- "regular" and "Asian." Not that they aren't good profiles, but you might want something different.
Another is that the stones do eventually load up and require cleaning. I'm not sure whether the user can do this herself on the smaller home machines, or must send the machine in for service. I can't overemphasize the importance of not only making sure your knives are clean before sharpening, and rinsing and wiping occasionally during the process.
Yet another, restricted to the older 110 and 310 designs, is the magnetic angle guid. The sharpener needs to pay attention and make sure the knife rides against the guide during its entire passage through the slot as the magnet really isn't very strong. Since putting the 110 and 310 on the market, Edgepro's abandoned magnets in favor of springs.
The machines are packed with instructions which tell you how many times to pull the knife through the slot on each side, how you should shape the stroke; how much pressure you should use, etc. If you no longer have the instructions, look at the instructions for the Model 120 on the Edgepro website. The 120 is a three stage sharpener, you'll have to think of your second stage as a sort of compromise between the 120's second and third stages.
Remember, once you've established the basic profile on stage 1, you'll touch up on stage 2 until it no longer works for you and you need to go back to stage 1. That means if you touch up your most frequently used knife every week or so, you'll probably only use stage 1 a half dozen times a year at most.
Stage 2 will true a blade as well as a steel. Whether or not you need a steel as well, depends on your knives, your board, and whether or not you want to "touch up" every other day.
A lot of "knife guys" lump Chef's Choice machines with the bad old days of electric sharpeners, deeming all of them unacceptable. Don't listen to them. All home electric sharpeners are not created equal.
Use it right. Clean it when it needs it. It will be your friend.
Edited by boar_d_laze - 7/16/10 at 11:47am