It's opinion, of course; I use MS's web-based editors quite a lot, and they work well for me. I almost always have access to the local client software, too, so

It's opinion, of course; I use MS's web-based editors quite a lot, and they work well for me. I almost always have access to the local client software, too, so most of the time it doesn't even really matter; skydrive is just a great cloud-storage thingy for my documents. For the times I don't have a copy of office on the machine, the web editors are fine. I haven't yet run into the concurrent editing problem, but it may well be a showstopper for some features. For note-taking (which is the common case I can think of), OneNote is arguably a better choice, and it supports concurrent editing.