We have several pieces of Calphalon One (not nonstick). I would say it is comparable to SS in terms of your questions. I use Barkeeper's on both my Calphalon One and stainless and have had no problems.

That said, though, I'm not sure that I would recommend Calphalon One over stainless. The initial attraction was that it was supposed to be more stick resistant. It isn't, which I'm sure is why they then came out with a NS version.

My money's now on All-Clad Copper Core. We have one large skillet and love it. But wow, is it pricey. Best deals are on eBay (new items, not used).

I have had Calphalon One for over a year, and it does not have any stains. It looks almost new.

If I cook anything greasy or oily it gets a dark shiny patina, that I use Bar Keepers Friend to remove. You don't have to scrub it hard, just light rubbing with a Scotchbrite and let BKF do the work. Once I fried eggs and got some stains that took a couple of washings to remove, but other times cooking eggs it has not happened.

Pancakes are one thing sometimes stick. Careful preheating eliminates sticking though. Potatos and vegetables need to be reasonably dry or they will stick when frying. Other than cast iron or non-stick, C1 is the best frypan I have ever had for stick resistance.

I took some courses at a Calphalon Culinary Center where we used it, and it was in good shape there too.

I like it, but as with suzyq3 I'm not totally sold on it. Sort of buyer's remorse, I wonder what All Clad would really be like. C1 sears and deglazes amazingly, but does need care. It is not for people that want cookware they can bang a metal spoon on the rim or throw in the dw.

I've had several pieces of C1 for a little over 2 years and I agree with everything deepwater said. I would add that you can use a green scouring pad on the C1 and not scratch it. If you do that with stainless steel you will scratch the surface. That's because anodized aluminum is much harder than stainless steel. I don't think those micro-scratches hurt the performance of the stainless, it's just a cosmetic thing. The C1 does have some nice design features; the handles and lid handles actually stay cool, the handles are ergonomic, and they look really cool.