Thanks for sharing Dan. I have a new 2153 here that I cut the squish band in. It has just shy of 220 PSI. It's still on it's first tank of fuel, so not even close to broken in. My 346 has a popup piston with just shy of 200 PSI. I'm anxious to get some time on the 2153 to make a fair comparison. It's not a perfect test for the popup/flattop debate. In addition to the piston difference, there's a 20 PSI compression difference, with the one getting past what you say is ideal. We'll see. Other than that, the two saws are close to identical in build.
Don't forget in this discussion, we're using chainsaws that run at WOT almost exclusively. We're not concerned with bottom/mid-range torque needed to come out of a corner.