The folks from RhodeCode noticed the exchange on Twitter that prompted the previous card and suggested I take a look :)
Source code is here with mirrors on both GitHub and BitBucket.
I think that's as nice as GitHub or BitBucket (sorry any Allura folks reading this!), so time to put my money where my mouth is and pony up the cash for a small RhodeCode instance and migrate my personal Hg repos away from BitBucket :) (Well, once the free trial period ends, anyway!)
In contrast to GitHub, BitBucket or SourceForge, which are like one big shared instance instance, RhodeCode's hosted offering is a bit more like getting your own Gerrit or GitLab server. I suspect, with that model (and the main benefit of higher payment plans being more registered users of the instance), it's a better fit for personal or business use than it is for open source projects.
That said, open source projects that can't afford the rates might be able to combine the RhodeCode source with the free tier of OpenShift Online or the offer of free open source project hosting from RackSpace...