I bought my SP3 i7 256GB at Best Buy. They had to order it for me, as they don't stock the i7's at all. When I got it home, I saw that it also had zero resistance between closed and the point where the resistance is supposed to increase significantly (30-degrees or so?). If I let go of it before that point, it would just fall shut.
Not wanting to wait another week for them to order a replacement (and considering this unit was already an upgrade/replacement for the i5 I had returned), I took it to a Microsoft store. At first they said that, since I was within the first 30-days of ownership, I should take it back to Best Buy. I told them that Best Buy didn't stock them and would have to order a replacement. They basically said, "Sorry 'bout your luck."
Then I asked them, if I have a problem within the first year warranty period, don't they take care of that on-site? He said yes, and, seeing where I was going with that, went to talk to his manager again. His manager told me he would take a look at it, and upon seeing the behavior of the kickstand, agreed to swap it out for me on the spot. He did not, however, seem all that happy about it. I simply told him that it's not within spec (as evidenced by the several we checked on display) and for $1500 I just wanted to make sure everything was as it should be. They gave me a new, sealed retail box, and I gave them just my tablet. I ended up with a free spare power supply and pen out of the deal.
The new unit does have a little play, but the kickstand basically stays at any angle I set it. I'm a happy camper now.