I dive with an Abyss as my primary and a Proton Ice as my Octo. Both breathe great - I just like the larger size of the Abyss, reducing the bubble interferance - but I also use a SeaCure mouthpiece to offset the weight and size. I also find that using an all metal second reduces dry mouth significantly for me.
My wife, on the other hand, dives a Proton XL with a Proton Octo because she likes the lighter weight and smaller size - she uses a Comfo-Bite mouthpiece (does not like the SeaCure).
I dive in colder water than my wife does, so the all metal 2nds also give me a more secure feeling when it comes to the potential of cold water freeflows.
We both dove Aeris and TUSA previously, with adjustable 2nds - and find that the Mares breathe as well, or better, with no need for adjustment during the dive. It did take a couple of attempts at "tuning" them to get them set where we wanted - but it is very easy to do on the Protons (a little more work on the Abyss).
I think you will be happy with any of them.