brotherhood_of_LAN - 2:44 am on Oct 10, 2013 (gmt 0)
I've an old account with them and the major downside I see is the amount of spam that is visible. I think it's a legacy problem from the way they used to display profiles and assets associated with those profiles, basically there are huge lists out there with valid yahoo usernames and their @ address.
I'm kind of indifferent to the UI, it sends and received mail :o) Seems fast enough but the page is a little heavy to begin with. I use outlook and am more or less happy with that so I wouldn't switch, but there are annoyances with Outlook's new format, particularly on the first page load and waiting for it to fully load before I can click on mailboxes.
They've already purged a lot of older accounts and I see they have a new signup form, requesting a mobile # with every new signup. Seems they're working hard to raise the quality of their user db.