We already had a thread of 2, but I don't begrudge another one, personally! ;-)
For me, it's the best improvement I've seen from a "Network Patch" since that first one for... Blazblue? It easily proves that whatever SNK had under the hood was very competent, and that the day 1 issues were a very unfortunate bug. No way could they have re-written anything as fast as they did, and have it turn around that fast.
Just for personal taste, Solid Delay > OK Implimentation of Rollback by a mile. I utterly HATE watching moves re-wind from block to hit, hearing the wrong sound effect due to this, and seeing proper reversals turn into blocked moves.
That's the most miserable kind of netplay I've had since the atrocious Hyper Fighting Netcode on early XBLA, which is my personal Turd Standard setter. (And I actually really, really played SamSho II and 98UM on XBLA, and KoF Neowave on Xbox BackCompat, and I still think it was much worse.)
I haven't had a match I'd consider "horrible" since the patch. A stutter here or there occasionally, but I expect that on a system that has Wireless play (that many probably default to) out of the box.
Along with party battle, being able to set up rooms with easy opt-in / out match making, and the Online training mode I don't hear many talking about, I think it's a very, very solid set of online options and netcode together. It actually feels like a feature set, rather than a fancy wrapper for straight P2P gameplay.