After having used Ernie Ball Slinkies for 20 years, I have discovered the NYXL range last year and I don't think I'm going back. They stay in tune almost straight out of the pack, and seem to sound fresh longer. They feel nice and snappy, maybe a bit less tension that other strings of the same gauge but at the same time there is something about the responsiveness. It's very hard to put it into words as it is such a subjective experience :) But to me they feel comfortable and snappy and alive. Also it seems like the output is slightly higher.
A bit pricier but given how they seem to last longer (or at least the degradation is more gradual) and with the satisfaction I get out of them, it's well worth it.