We are in the final stages of install of a mini-split system. We have two units...one is 48,000 btu (handles 8 zones) and the other is 36,000 (six zones). The system is Mitusubishi, which we thought was the best out there (at least for us). We have a mix of equiptment which was chosen with the idea of being able to "hide" the system to keep the house's period feel. We have three types of heaters. The ones which mount on a wall, which we have hidden in soffits in the basement level and the two that are in bedrooms in the family area are hidden in custom built window pelmets. They are basically silent IMO (you can hear a rush of air when it feels the occasional need to spit out extra heat but that's fairly rare and still really quiet). Then we have units that are boxes people would install in metal boxes on the floor (which could be hidden like a water based heat thingie...ummm what are those called? The pretty iron ones LOL) but because we never had hot water heat in this home we decided to hide them in modified furniture. The master suite has one that is hidden in a tall secretary. A drawer is removed and deep gold metal screening fills the gap where the air flows out. Beneeth the piece (which is on legs) they are making a screen to hide the part you can see on the floor. (We took them out of their big metal box housing so they would fit which was done by the installer and is safe). The other similar unit is in an amoire. I will say this about those two units...they are powerful and we keep them at the lowest setting otherwise the rooms get too hot. But those rooms are going to get much larger with the restoration so we knew this going into it.
The main floors are heated by units which are hung on the ceiling of the basement and ducted to boxes we cut in the floor above. From the main floor all you see is a pretty floor register. The pieces are all hidden in the soffits down below so you don't see all of the ductwork and the boxes when in the basement.
My son's unit is a wall mounted unit in a room that is about 15x18 ish with ten foot ceilings. It runs on low and keeps his room comfortable, but not too hot. It's basically silent and does not disturb him when sleeping, nor does the air blow so hard it bothers him.
The part we are having done now is all about hiding the units (all that soffit stuff as well as building the window pelmets). The units are fully operational and they work very well, very quietly, and make this drafty old place finally comfortable. We anticipate they'll be even better when we finish the restoration and all of the windows have been rebuilt etc. I love being able to change the heat on my ipad

or phone or computer. Very convenient verses having a thermostat in each room (ugly) or having to go down to the main system to make changes.
We anticipate the pay out to take about 70 years

and no that's probably not an exageration....the system is very expensive....but so far we think it's a great improvement to the old box.