[jfrisby]

If it were just features, I'd probably agree with you, but Mail.app in particular (doubly so on desktop) seems to have serious issues with syncing of mail, handling of connections when there's non-trivial packet loss, maintaining its internal database consistently/correctly, etc. Some of this may only be an issue if one has many accounts and/or large inboxes but for those of us with, say, an iCloud account, a normal GMail account, and a handful of Google Apps accounts -- and email history stretching back many years -- it's a serious problem.