I'm a recent switcher and so far I've picked up a
black Incipio Feather case and a
GTX black keyboard cover. I haven't had too many issues yet, but with the Feather case other than some sharp edges around the close latch and palm rest area, and also fingerprints. I'm pretty happy with this case so far, and it doesn't give any noticeable weight. I purchased the Incase hardshell before the Feather and it felt like it added a ton of additional weight to the computer. I also noticed scratches where the little clips would latch onto. It was a nice case, just didn't like the weight.
I would definitely do some shopping around as these cases getting pretty pricy pretty quick.
As far as the keyboard cover goes, I have no issues. It does what its supposed to. If you use your keyboard back light, I would probably steer clear of the one linked above. You can see the lights around the keys, but the letters do not light up. I've taken this thing off maybe once to wash it and it was like new again. As far as the keys go, having a cover does make the keys a little harder to push, but after awhile you get used to it. I make little errors here and there, but overall I'd highly recommend purchasing if your looking for protection.