Yes, I was a tester. I had an original s900 model that I pre-ordered long before they were first available and got from one of the first production runs, as far as I know. I tested several versions of the s9xx Saturn prototype as well as several versions of the specialized prototype. At one point one of the reed switches in the original crank died and they replaced it with the current (at the time) model. Also because there is no actual difference between the compact and standard versions except the bolts of the spider, I had it changed out to a compact at that time, and was only out the cost of 110 the BCD chainrings.
The s9xx cranks all use the same interface, so the spiders are the same (except obviously compact vs. non), and s975 is immaterial. I'm not sure what the point is in all of this; they've gone through several iterations of the physical as well as electronic implementations, but if it works it works and if you have a problem they fix it. If the point was that you aren't going to get stuck with old technology, then I agree. I'm not trying to be argumentative, I'm just attempting to provide some background and correct a factual error that the Cinqo spider has never changed. Note that the crank and Cinqo do not need to be purchased together, so there is not necessarily the concept of an integrated s975 power meter unit... there is no reason someone couldn't have taken an older Cinqo and slapped it on a newer crank for some reason. If you look at it in isolation as s975 cranks sold by Quarq with power meters already fitted, then your statement may very well be true, but I haven't been following the recent development closely enough to say.