Played with them yesterday for the first time after breaking them in around the house. And wow! They really do work as rumored.I went up a half size, and that works perfectly for me, but in my case it's because I have a medium to wide foot.
The upper does break in and you do get extra space so it may depend on how roomy you like your shoes in the long run.
I played four sets on Saturday in my VC4s, and my feet were really sore--especially around the calluses on my big toes and balls of my feet. I used an hour of sick time and limped around all day from right knee pain.
Then on Sunday I played six sets in the GP Turbo. No soreness in the feet or joints--just the muscles, where you want to be sore. I'm sold. I'll wear out this last pair of VC4 and then I'm switching full time.
And for comparison's sake, the VC4 are also new. I've played in them 2-3 times.