Ran a 124 S&S fully modified in the fatboy. Might know a thing or two about Harleys. There is no way on this earth that a 124 S&S With Everything else including primary runs even close to the Screaming chicken stuff. Cost of a fully modified S&S 124 is well over 20,000 dollars and as far as reliability No the screaming chicken is more reliable due to the stroke of the 124. Weak results on the Dyno. I would look into fuel injection system and air intake then find a suitable tuner.
I'm pretty sure I know what I'm going to replace my RM with in a few years.
I've always been fond of the Road Glide Ultra and figured that one would end up in my garage at some point in time (Not with the current rear suspension travel though).
With this... HD has a lot of catch up to do before they're back on my radar.