I installed my own Sanyo mini-split inverter style system two years ago. It was primarily installed for cooling a previous open porch that was converted to living space. The condenser unit is connected to two, wall mounted air handlers. I've very pleased with the unit, very very quiet both inside in out. Fan speeds vary, depending on demand.
Installation had two distinct parts. The home improvement part and the HVAC part. I did both. It was a challenge getting the air handler's mounted and the electrical, HVAC and drain lines installed. The porch was easy because it was new construction. The existing master bedroom was much more difficult. Drywall removal, new electric lines, etc. The big concern is the flare fittings and their seal. In my case they are covered by drywall. It's got to be done right or repair gets you back to step one. The master bedroom unit allows us to not operate the central A/C when sleeping in all but the hottest of nights. A considerable savings.
HVAC interests me and I have taken all the courses offered at my local public tech school/community college. I have a MD apprentice HVAC license and the EPA certificates for handling refrigerants. I bought all the needed tools and equipment. In my opinion the line sets should be pressure tested with nitrogen as the installation goes along. This precludes closing up something with a leak. I did this. Some will tell you vacuum is good enough. I don't think so. R410 pressures are quite high and you need a robust test. The most a vacuum test can do is 15 psi. A nitrogen test can do 100-200 psi.
Evacuating the lines requires a vacuum pump and a micron gauge. Some cheat and just let the pump run extra long. I think this is taking a chance. My line runs were within the factory charge limits and i didn't have to add additional refrigerant. I was prepared to do this by weighing in refrigerant with a scale. This was my first install and I learned a lot. There were lots of back tracks along the way but in the end the operation and satisfaction is outstanding.
My recommendation for homeowner would be not to attempt the HVAC part of the install. There are just too many expensive tools to own and more importantly knowledge you don't have. Concentrate on proper equipment selection and physical installation. I'd own a nitrogen pressure regulator and rent or borrow a tank for testing.