Gentlemen, it appears that your focus is wandering...
...is it not an "apples/oranges" comparitive analogy to cite a 45* V-twin, a 70* V-4, and a 180* opposed flat six in your commentary? Surely, you are sufficiently astute to acknowledge the inherent potential power and subsequent limitations unique to each design..
But since you have broached the subject, permit me several observations:
As stock bikes all three have considerable merit, but none are perfect. Consider the V-Max, an outstanding and highly efficient motor in a chassis it doesn't deserve, suffering indeterminate handling in every attitude but straight ahead. I've only seen a few (arguably "stock") which actually ran in the 10s (with outstanding pilots); most run in the mid 11s, and some only in the 12s. I'm certain the operator is a salient factor. They can be rebuilt, but the availablity of parts other than dealerships is somewhat limited. As for the Valkyrie in stock form, the 12s are consistently comfortable and it's still an extermely reliable machine. If you wish to penetrate the 11s, it can get somewhat expensive... the 10s even moreso. "Can you say 9s?" Sure, can you say 75%+ of the original cost of the bike? Priced any factory speed parts lately? There is a small aftermarket which could supply your need for speed, but it is very expensive and somewhat exclusive - but don't dispair, if your funds are adequate you may be invited... If you want to rebuild a Valk and keep it reasonably stock (and therefore reliable), that's a much more manageable proposition (but not cheap).
A Confederate Hellcat is a minimalist design intended to be easily rebuilt by the owner, for generations. The V-twin aftermarket is a staggering enterprise whose annual cashflow is described in terms of billions (US); one may reasonably expect it to continue in some form. A Hellcat in stock (EPA/DOT approved trim & state of tune) will run mid to low 11s consistently. Massaged by a competent tuner and ridden well, it can play in the 10s at will. This is not idle speculation; anyone can watch as Confederate tests these bikes in public at open tracks and events. Getting into the 9s would likely negatively impact the reliability factor, after all it is still only a (somewhat dated?) 45* V-twin. The chassis is more "road-race" than cruiser (the sportbike crowd actually has an easier transition/adaption phase than cruiser riders at test ride opportunities/events). The downside is, of course, the initial expense (cost of the bike) at about $25K (US), but a Confederate is intended to be around long enough to be articulated in one's last will and testament.
How much will anyone be willing to "invest" in that V-Max or Valkyrie... over the next generation or two? I would likely just opt for a new one every three or four years, but by the time I'd had three or four "new" ones, I'd have spent considerably more money, wouldn't I?
Lest we lose sight of the facts, let us review the dogma... Motorcycling is fun, if you're not having any, go do something else. Motorcycle manufacturing and sales is about money, if you don't have any, you can't play. Marketing is about seperating you from your money, if you have some - they want it. The trick is to have as much fun and keep as much money as you can over the long run... and that's called life.