Yup. No way for end-user to upgrade firmware, download configuration software etc.
Nothing is serviceable. You just replace.
This is not entirely true. It depends on the type of customer. In the Higher-Ed space, Crestron, AMX, and Extron all have programs to train and support end-users. We have two certified AMX programmers on staff, one Extron, and Crestron has offered a similar program. Extron even pays some travel and hotel expenses. All three companies have been excellent in terms of issuing RMA's and quickly turning around repairs. (we have a single Crestron system that was part of a turn-key simulation lab. It has been solid, but the few issues we have had were dealt with rapidly.)
Extron's control systems offer pretty powerful programming options that are bit easier for a 'non-programmer' to get up and running on. I agree with Craig H. that once you make the jump into full control systems, the world opens up in terms of making systems simple to use
the way your users want to use them. <-- That there could be the key point.