They all have PRO and CON.
From left to right.
S5 is really stable. With 2 Delta Fan I can run it cold at 1200gh and 393.75 (he got outside air -10 )
Avalon is the quiet one. I cant hear it and that is awesome. He trow a lot of hot air but that ok since he is quiet. I get 1th steady.
And the last one is the SP20. A beast but loud. The S5 was loud but I manage to find a better fan. Will maybe try to look for the same think on the SP20. To make it quiet I use it with Philipma1957 setup and get 1144gh and as much silent it can be. (Fan at 6) Still more loud then the 2 others.
Total of about 3.5th and Im happy to have 1 of each.
Im waiting for next gen before buying. Each miner have PRO and CON so it depend what you need.