2007 RKC, big bore kit, true dual exhaust, SE Super Pro Tuner; over 16000 miles and it gets better with break-in. Just got off my wife's brand new 2009 Street Glide and my transmission is way more quiet. Haven't done any maintenance except preventive, E.G. oil changes, lube, adjustments. We rode loaded down, two-up to Sturgis and back (almost 5000 miles) with no problems.
I am awaiting a neutral switch that may have caused some dash lights to come on twice, but they haven't come on again. Also, had some issues with the cruise control but they haven't resurfaced in quite some time either?
Anyway, I am very happy with the reliability of my 2007 FLHRC.
I am using:
Mobile 1 V-Twin (Engine)
Spectro 6 Speed (Trans)
HD Formula + (Primary)