I had the RFX 8240 takeabao mentioned and absolutely loved it. The 8240 & 8250 are rebadged Denons. Look great and sound great. They are deadheads though, with no fancy built-in options like EQ/xovers/time alignment/etc.
From what I'm told, the earlier RF HU's were built by AC Delco and were pretty solid headunits aswell.
I wouldn't touch anything from their recent lineups, however.