I extensively play tested all three of these saxophones (and twenty-seven others) between February and March 2018. I remember being surprised by how good the Selmer Series III horns were. I went in thinking that I would like the Reference 54 or 36 better for what sound concept I had, but I came out thinking that the Series III was the best current model Selmer. I thought the tone was the most neutral with the Series III and perhaps a bit brighter. Ergonomics were excellent on all the Selmer horns, as well as the professional Yamaha and Yanigasawa horns.
Comparing the Yamaha 82Z-II, 875EX, and Selmer Series III saxophones specifically, I would say that the Series III is more resistant and closer in tone to the 875EX than the 82Z-II. Between the Yamaha saxophones, the 82Z-II was lighter in weight, but I actually preferred the Yamaha 875EX to both of them. The particular 875EX horn I played just knocked my socks off and I bought it on the spot. It's 22 months later and I absolutely love the 875EX.
Here's the list of saxophones I tried in case you have questions about these horns:
Cannonball stone series mad Meg tenor
Cannonball stone series nickel tenor
P. Mauriat tenor, forgot the model
Dakota Sax tenor
Keilwerth SXR90 lacquered raw brass
Keilweth SX90 gold lacquer
Jean Baptiste Tenor
Conn 10M tenor, multiple
Selmer mark VI, multiple
Selmer Reference 54
Selmer Reference 36
Selmer Series II Jubliee, multiple
Selmer Series III
Yamaha YTS-26
Yamaha YTS 875EX
Yamaha YTS-62-III, multiple
Yamaha YTS-82Z-II, multiple
Yanigasawa TWO02, multiple
Yanigasawa TWO10, multiple