You're getting this stuff for free, and I very much doubt it's garbage, so don't look a gift-horse in the mouth. In fact, I rather like the looks of this set. Pricey, but that's not your problem.
That said, I would suggest that you read this article
. It will tell you a great deal about different kinds of cookware, their advantages and disadvantages.
As you will see, it's true that stainless is not a great metal for cookware. But this isn't straight stainless: it's a complex sandwich with stainless on the outside only. The idea is that you get all the advantages of stainless (i.e., it doesn't stain much) with the advantages of copper and iron (thermal conductivity, heat retention, etc.).
I find that the oven-proof thing is quite useful, as it makes braising and even roasting, especially roasting smaller things, a lot easier: you don't have to haul out a huge roasting pan just to roast one chicken, but can use a saute pan or even a skillet instead. This not only makes cleanup and handling easier, but you actually get better results because the chicken isn't shielded from the oven.
Do not expect that because this is stainless, it will never stain. It will. But it won't stain much, and care is pretty trivial.
Glass lids are useful primarily if you are cooking something for quite a long time. At first, steam promptly fogs the lid. But after several minutes or more, depending on what you're doing, the liquid actually forms sufficiently large droplets which run down the surface that it's sort of like looking through a car window in the rain (without wipers, obviously): it's pretty distorted, but you can see. I find that this is primarily useful when you want a very slow, steady simmer, and want to be sure you don't have a real boil: the glass means you don't have to lift the lid to check, which helps. Good for rice, too.
Would I buy this set? No. I already have equal-quality pans to everything in it that I'd want, and there are a number of things here I wouldn't touch, like the little wok (although it is a useful pan for making certain sauces). But you're not asking if you should buy it, but if you should accept it as a present. YES, is my answer. But then chuck out everything that is actually replaced by it. And eventually, sell the odd piece that you don't use. The point is, don't think of it as a block, a permanent set: think of it as 8 separate pieces of cookware (6 of them with lids).
Oh... and happy holidays!