I switched at the 1k service....had the dealer put in the Syn3.. at 3500 miles I changed it myself and used Brad Penn Synthetic, just changed it again at 7000 miles and am currently using Amsoil.
Bought my RDK new in 2000. Ran HD oils til 68k miles. switched to HD Syn 3 in all 3 holes at 68k miles. Changed all at regular intervals and now have 104k miles on my bike. No problems so far.
Changed my 2004 ultra asap when i got home to amsoil 20w50 oil & primary & amsoil sae 60 high performance oil in tranny & the screaming eagle 6 speed shifts so much better ecspecialy on down shifting .