Me and my friend have been having an ongoing arguement about this. What i've been doing is, on the cluster, upping the weight by 5-10 pounds. The rest might not be right on 30 seconds but its under a minute forsure. He say's not to and to just lift the same weight all the way through. When i up the weight its just when im stuck and not improving. I have been trying to do this as a way of breaking through. He said it was putting too much stress and effecting recovery. My personal experince is that it works, although not all the time.
We've decided to get some imput from others to try and settle this.
(btw this is with HCT-12 obviously)