The mitsubishis are known to be top of the line. But I don't like the way their indoor units are styled. Seem very basic for such an expensive unit.
I have a full warrantee on mine because a licensed tech did the final hookups, pump down, leak test and release. And I've spoken with the manufacturer regarding this as well. All in I'm more than a 3rd of what you paid including Me paying $90 per hour for a contractor to do the final connections- on 7 indoor units and 2 outdoor units. That added up quick.
I'm not knocking you for having a company install it, please don't take it that way. But not all of us can afford a Cadillac when a Ford Focus will do the same thing and last just about as long.
contracotrs are making a killing off installing these and I too got quotes that were all similar to yours for just a 2 or 3 indoor head project. They were laughably ridiculously expensive for what amounts to a moderately difficult project that most homeowners can successfully do on their own and save a lot of money.
I'm not disputing any of your thoughts ..... remember the OP's price difference between the units (one being Mitsubishi) is $800 per 3 head set. He is having them installed. I agree -- too much of a premium IMO for many of the installs ... especially with new construction where the lines can be inside walls -- fast instal.
I have actually found the Mitsubishi heads to be less intrusive vs many of the others -- they are wider .. but, they don't stick out as far as say the Fujitsu. My LG artcool is interesting .. but, not really any less noticeable. Less is more when it comes to hiding them -- any lights, displays or trim only calls attention. That said --- once they are installed for the most part you forget they are there.
The Mitsubishi heads with the eye and split outlet really work and can be a bonus in situation where people are siting and relaxing. If you read the trade publication all agree they lead in the firmware that makes them work -- especially the multi head units.
With the speed of change in the industry -- it seems that prices are falling .. and the differences between brands less. There is a lot of movement in the ceiling and other style heads to capture more of the new construction market.
With the technology available I'm surprised there are not more DIY -- or installer friendly units around. Heads and compressors with the sealed fitting -- precharged line sets in various sizes. Even flex hoses pre charged. We can make auto AC hoses and fittings last 20 years -- why not the same technology?