Interesting. Is this a Delta-licensed product, or a Delta product made by Delta here in the US? Let us know how it flushes. Let us know the china quality and where it is made. I guess there are no standard parts in it, looking at how it's laid out. Any explanations of the merits of any of them? Obviously, you're not going to find that fill valve anywhere but from Delta in 10 years, and it's not going to cost $10.
What could the merits be of having the fill valve feed from a braided supply that enters the top of the toilet? Fewer penetrations in the porcelain below the water line? Is there really a significant problem out there with leakage around the fill valve penetration in the porcelain (where it's in the same place it is in my American Standard model from the year 1927)? My 1927 toilet doesn't have that problem, and I just installed a new Korky fill valve in it for $8.
I saw in another post where Terry believed that somewhere between 2.5 and 3 inches was the ideal flush valve size, that 3" might be too much. Interesting that Delta went for "the biggest" at 3.75", which isn't necessarily optimal. Kohler tried that previously (wanting to be "the biggest"), then backed away from it.
Finally, I am curious about the apparent trend, exhibited here, towards reducing or eliminating the opening at the top of the overflow riser. I notice that Korky has, in contrast, moved towards a wider-diameter riser, which really can keep the water from overflowing the tank in the event of a runaway fill valve. Everyone else, it seems, has narrowed the opening at the top of the riser, which -- unless I am missing some design feature that I can't see -- would seem to reduce the toilet's ability to keep from overflowing in the event of a fully-runaway fill valve.