Mine weighed 74gm for the pair.
I've used them a little, up until an accident I had early this month, causing a couple of cracked ribs and a torn meniscus in my right wrist.
Fitting was easy, I followed the marks created by a set of Keywin cleats on an old pair of shoes, and used the SPD mounts. I did find the screws were canted by off center holes, but a drill fixed that. I did find that the cleat would float with just the two screws (I couldn't get them tight enough) so I added two screws in the front holes in the cleats, drilling starter holes in the shoes with a small drill bit for the supplied self tapping screws. I was worried about fitting four as supplied because I thought it would contribute to the shoes being too hard to roll off the pedal when removing my foot at stops, and I was right, it took getting used to as it was. So did the small area, and the accuracy needed to get your foot in, but that's no different to Speedplays, which I tried once (too much float for me).
I'm not sure if I notice the weight difference, but it feels different, maybe because of the lack of float, there is some slop in the Turcite sleeve, and this allows some movement, so it's not too bad. I used to use cleats and straps back when the M71 came out, so the lack didn't seem to worry me. I'm going to start riding with Keywins when I get back on my (new) bike to see if I feel any difference.
One thing I did feel was the small area, make sure you have some real stiff soles on your shoes, I feel that they would be okay for Doubles though, on Northwave carbon soles, so your experience may vary.
Overall I like them, time will tell if they grace all my bikes (normally three) but my real light bike will keep them, and that's the one that gets all the performance rides.