Racer, I know you have had two SuperBuzzes and now have the 5'3 Mr. Buzz. I have had all of the offerings in the Buzz series (Mr.Buzz, SuperBuzz, BuzzSaw, G-Buzz, 2x4). I loved them all. I think the Mr. Buzz is the most dramatic application of the design and the 2x4 is the most 'conventional' if the HPSB is the baseline for convention.
My guess you have tasted this in the Mr. Buzz compared to your SuperBuzz. Everything that I reckon you think you would get by stretching the outline with a BuzzSaw you get (little more glide, little more rail line, etc) with the short radius arcs with the double concave, tail rocker, continuous rocker combo on the SuperBuzz. I had two BuzzSaws the last one being more appropriate to my former size - 5'9 x 19.2 x2.2 Sk8 deck. But since I surf East Coast windswell beach break that is mostly short, quick and dumpy while being crunchy and punchy the more extreme features of the Mr. Buzz are exciting and helpful for my wants. For reference my Mr. Buzz is 5'5 x 19.5 x 2.25 sk8 deck and feels really good for me at 5'10 x 195 x 43 yrs old. I also surf my Mr. Buzz in literal thigh high waves with a 5/4 and boots and gloves so long as the wave is curvy. My experience with all of the Buzz Series boards is that they do very well with curvy/bowly waves of any size. I have no idea how you make distinctions for them with the power and size of HI's waves.
I imagine if I surfed longer period waves I would like the BuzzSaw if not just at 2x4.
For reference, I liked the SuperBuzz more than the BuzzSaw for smaller (waist high) and weaker waves but both worked for me.
My Stretch quiver is now two boards, 5'5 Mr. Buzz and 6'2 2x4 swallow tail. If I were to add one, it would go with SuperBuzz or G-Buzz, just for better paddling in weaker small waves.