If anyone needs good recommendations or info, I am in the wholesale business of A/C so I know alot of the contractors.
I can't sell equipment direct, so please don't ask, but if you need something I can get you in touch with a trusted company and work with them and you to help get you a fair deal.
I represent Daikin products. I am a commercial guy, but I know the residential products as well as the ductless products.
A service by a good contractor can be a good idea. Changing filters and good maintenance are key to long life. The most important thing about getting a new unit though is a good install. The best unit with a hacked in install is going to cause heartache.
During a "tune up" good contractors can catch things like weak caps, pitted contactors, compressors with high ohms, dirty coils, condenser fans on the way out, etc. All those things can lead to failures at the worst time of year.