Gee, I'm using Opera Next on a non-retina MacBook Pro... and I'm considered unique among a paltry 3.6M samples. On a site that's *extremely* likely to be visited primarily by Firefox users.
As a long time Opera user, this does not surprise me at all. I cleared my 'browsing data' for the last hour and tried again... a 50% reduction in uniqueness! Huzzah