What's the difference between lutron and knx?
Lutron is Brand, and KNX is a protocol.
KNX is a protocol adopted mostly in mainland Europe, it has many different manufacturers you can choose from for integration.
It also covers many different sections of integration from lighting, heating, AC, irrigation, appliances, almost anything you can think of.
Programming is PIG - horrible using ETS.
Lutron is probably the biggest brand in the world for lighting, they invented the electronic dimmer in the 60's.
Lutron also do window treatment - shades, blinds, ventians, etc.
Lutron have heating and AC integration, however I would stay away from that personally - but the lighting and shades in my opinion is the best you can get. but you will pay for it.
Programming is amazing, with easy to use GUI.
Mick