I like Loxone a lot. I have installed 4 systems so far. Most have used their air technology, which is a meshed system. The air system will automatically workout the mesh so no need to tell the devices how to hop back the the miniserver. So if you change a devices location it will sort itself out.
I also like the fact that Loxone can talk to a variety of non Loxone devices, it even talks to my washing machine. I have successfully used Shelly devices with Loxone, and this is fairly straight forward to set up. I even wrote a tutorial about it, in another post on here.
Regards to sound, you might want to look at Lithe Audio's wifi enabled speakers. They do an xml plugin for Loxone. One of the owners of Lithe has Loxone in his home.
Lighting- in my apartment I use a combination of Tree and Air based lighting. which works well. I like the fact that at night I can have lights only coming on at 15% brightness so if I wake up during the night I don't get blinded when going to the loo. You could also use Shelly modules for the lighting and get Loxone to control it. I am currently working on an install for the new year where I need to install 7 extractor fans these will use Shelly 2.5 modules, one output switches on a light and the second output controls the fan. All this is then controlled by the Loxone system ( I installed about 3 years ago for a client), so if the light is on for more than 3 minutes the fan is then switched on and then when the light is switched off the fan switches off five minutes later.
Loxone is very versatile. It is also very modular, so start with the mission critical stuff and expand out from there when time and budget allows. My lounge and bathroom are fully under Loxone control and the kitchen and bedrooms are still normal. One last important thing is you can use any type of switch with the standard Nano Air module. May not sound like a big deal, but you don't want to have to do a Loxone appreciation course everytime friends come over. Loxone do do their own touch switches, but in reality I very rarely install these for clients.
Hope this helps.