[sleighboy]

Use it with a team of about 10, for almost a year now. Interface with customers via email, SMS and chat. It is universally liked in our group. The internal discussion on different communication channels is wonderful. The API is well documented and quite permissive as to what you can do. Keyboard shortcuts galore. No direct IMAP connection now, but if you have GApps it works well. UI seems snappy, and I've seen no issue leaving the tab open for weeks straight.

I have been the most impressed with their response to feature suggestions. I raised a few points for improvment using the general help chat in the interface and to my surprise saw my suggestions released as a feature a few weeks later. Granted, they were minor interface items, but the fact someone actually took the time to consider it and slot it in for dev time means something to me, being on the other side of that usually.