It basically comes down to the properties of the steel they're made from, and how sharp they are.

It sounds like you haven't sharpened your knives in a good long while. And judging by your question, you've probably never been taught how to properly sharpen a knife.

I'd suggest getting yourself an EdgePro Apex shapening system, and their videotape about how to use it, and go to town on your Cordon Bleu knives. You'll probably end up with knives that are sharper than what comes in the Henkel's box you've been thinking of getting. And if the knives you have happen to not hold an edge (unlikely!), you'll still need the shapening set to take care of your new knives.

Here is a link that might be useful: EdgePro

SolarPowered is exactly right. The steel has two conflicting properties. One is hardness. This is the ability of the knife to hold an edge. The second is ductility. This is the ability of the knife to withstand flexing or impact without breaking. These things are created by both the chemical composition of the knife and how it is 'worked', forged to harden it then heat treated (annealed) to soften it a bit. They try to keep the edge hard and the spine softer.

Some of these components can also help the steel restist corrosion (nickle, cromium, moly etc). Hence the term stainless (which really means stain resistance).

You will typically find a hardness indication of the edge as a rockwell number. You'll see a little dimple near the handle where they test the blade. Values of 57-60 are pretty hard. You are less likely to find any indication of the amount of annealing done but the major manufacturers do a good job of this. The most common problem you'll find is over annealling which makes the edge too soft. They try to catch all of these by doing the rockwell test after the annealling is done.

Simple carbon steel can be sharpened to amazing sharpness. Stainless will typically not be able to be sharpened to quite the same level but because it is harder the edge lasts longer (but again, it is harder to sharpen)

Other things that affect a knife are feel of the handle. Edge geometry. Blade thickness. Balance of the blade. And general aesthetics.

Anyway, after all that (because you asked) I agree with SolarPowered, get a good sharpening system and I think you'll find your current knives are just fine.

Ken

In my opinion knife "sets" are only good for decoration, and using up counter space. You can do pretty much anything you want to in the kitchen with a good chef's knife and a paring knife. Add to that a serrated slicing knife and a decent pair of poultry shears, and you'll be invincible. So, invest the money it would take to buy a big set of knives into a couple really good ones, and you'll be better off. Also, I think your knife skills become better if you only use a couple different knives. Your hand gets used to the feel and balance of a knife, and how it handles.
And of course, like SolarPowered and Ken said, sharpening and maintenance is crucial.

Ben

I should have mentioned in my first post: If you want to buy some new knives because you like them better, by all means go ahead! That's a perfectly good reason to buy new tools. ;-) It's only if you're thinking about buying new knives because the ones you have don't cut that I'm recommending against new ones.

Either way, you need proper sharpening tools to keep them sharp. :-)

I think that the weight of the knife and the balance in your hand is very important too. The better knives that I have are heavier than the inferior knives. I can balance the knife in my hand without griping it and it doesn't fall off - not that I would recommend trying to cut with the knife in this way.

A steel keeps my knives nice and sharp - that is....when I remember to use it. What a difference a well honed knife makes to your prep.

I agree with Ben. I use just four knives - a serrated knife for slicing bread, etc., one of a variety of small paring knives, a plastic serrated knife for lettuce (the lettuce doesn't brown after cutting), and - best of all - my new Santoku knife for just about everything else. I got it about five weeks ago and it has changed my attitude towards cooking! This knife is fun to use, versatile and fast. It cost $70 on sale and is worth every penny. I'll never be without one again!

Check theknifeguy.com if you like your old knives and want to get them sharpened. The service includes a box to send them to him and postage three ways--he mails the box to you, you pack the knives and send them to him, he sends them back in a week. Great service.