graeme_p - 5:18 am on Jan 12, 2012 (gmt 0)
My take on this is that they did it because Google does it, and then found that lots of their user base does not like it.
Personally, I have had no problems so far: my extensions all seem to work, bar one which has not been maintained for a while. I was initially a bit sceptical, and I still dislike the system on principle, but in practice it has worked well.
What exactly are channels? I thought they were just designations for differentiating between nightly, experimental, beta and stable versions? How do they affect profiles? I just let it update from the repos, and so use whatever Ubuntu updates to.
I do not use multiple profiles (never saw what use they were either).