I have a two-zone split system in my home, and I put one out in my detached garage, which became my office after a second kid. I hired a company to put the one in my house, since it was my main house and if I fucked it up I'd be paying for it. The one in the garage I did myself, with help from my uncle who is just a fountain of knowledge, which came in handy. Getting the evaporator up on the wall, no problem, I ran the electrical, put it into the panel in the garage, no problem. Only place where I ran into an issue in my knowledge was charging the lines, but I don't think it's totally beyond learning.

Anyway, Carrier in my house, and Pioneer out in the garage. As far as how they function, the comparison is a bit apples to oranges, but the garage is fantastic. I went with 19 SEER v. 21 in the house, and I think it's great for the garage, I sacrifice a little efficiency for it to be able to cool/heat rapidly. I use it in the winter and summer, and I'm in Zone 6A for reference. This will be third summer for them, the Carrier system (May 2021), and the Pioneer was August (although I might not have installed until Octoberish, because I take my time doing things.

Yeah, just anecdotal. I think the main difference I've read is warranty support. You will not get comprehensive warranties unless you go big name with professional installer. It reeks of bullshit, but I guess I get it, it's not something simple.