It's been a couple of weeks, but I'm going to chime back in here...
I've now got my matrix switch up and running and frankly, it's pretty smooth and transparent. I decided to just leave the sources on all the time, and that seems to work fine. Any TV in the house can pick up and turn on with no issue.
I definitely understand the argument with DirecTV's multi-room viewing as well as streaming boxes, but the maintenance of that setup can get annoying too. Every DTV box has it's own guide (and I'm fussy and like to have a custom channel list just to cut out a lot of the garbage I'll never watch... but it needs to be maintained as DirecTV adds and removes channels sometimes - on each box). Admittedly, not a huge deal, but just a thing that always annoyed me. Same with the streaming boxes. We kept buying them for different rooms and stuff and they all have credentials that need to be managed, etc... Now none of that really justifies replacing the whole setup with a matrix. As wkearney suggests, you're definitely trading one set of problems for another (likely larger) set. So from a 'simplicity' or management point of view, there's not much of an argument here.
I was interested for a couple of other reasons though. I have plans on adding a couple of more TVs in the near future. With the matrix, this means one new $200 receiver box, and I get all the sources. Done.
Same for if I buy a new source of some sort (not sure what that might be right now). I plug it into the matrix and get it everywhere.
Again, this still doesn't make the case for a matrix switch, but they definitely help.
There were a couple of other small uses that I really liked too. When the kids are upstairs and watching TV, I like being able to just turn on to the same source and see what they're watching (even if I just mute my TV) - how much time is left, etc...
I also like being able to play XBox in any room as opposed to having to close myself up in the media room. The latency is super low, and with wireless controllers, it actually works pretty darn well.
So again, ymmv, but so far I'm liking this thing and now that I'm past the setup and figuring out the audio issue, it's working awesome. From a user point of view, I'm pretty sure most users wouldn't know the difference.