Disclosure - EMCer here.
@NateAmsen: I'm sure I speak for HP (in a sense!) when I say: "I'm very glad you're happy with your choice!". This is why I think it's good that at the same time there are "net new" AFA designs, that the older, more mature Hybrids are getting tweaked for all-flash configurations.
For the EXACT reason you picked your 3PAR 7450 (maturity, familiarity, specific data services), we do all-flash VMAX3 and VNX2 configurations, and they are VERY, very popular, and have lots of happy customers - just like you are with your 3PAR hybrid, configured with all flash.
But - all sorts of things, including the IO path, and RAID configurations you describe (which would be similar to on a VMAX3/VNX2) are examples of things that, if a developer was assuming a 100% NAND persistence layer, they would do differently (and almost all AFAs do differently).
Not saying "100% flash configured hybrid/cached array = bad!". They have data services like the ones I mentioned and are the right answer for some customers.
I am saying that true AFAs (designed to NEVER have a magnetic persistence layer) are the fastest growing category in SPITE of none of them having VMAX3 or 3PAR like data services.