I'm very pleased with my 1M/E - but I'm actually quickly running out of inputs and outputs for any production that get's moderately more complex than a regular concert show to projectors and tape.
We're sometimes running studio productions as part of the regular shows, and often have to run these through a separate switcher + control room due to lack of inputs and outputs. We'd probably have really good use of a Videohub with these kinds of productions, where you want separate monitors everywhere with lots of different signals: One for the projectors in the hall, which should have a separate mix from the stream, the studio should have both themselves and also main PGM out, audio is running everywhere and is de-embedded from SDI streams and changed around, the audio guy for the studio needs a monitor to see all the people with mics there if he's not in the same room, a local confidence monitor in the control room for the projector output is nice, etc etc.
What we've found though, is that most of the things we want to do, we can. Often we need a little bit more outboard gear, but we can generally achieve most things.