I use "full manual" mode on my road bike. I didn't like the syncro or the auto-changing of the cassette. I'm sure some people love it though.
On my TT bike the only option is full-syncro. I was sceptical at first, but it's fine as I tend to spend most of the time in the big ring and you get to know at what point it's going to auto change up/down on the front.