For me, it all depends on the individual print. I'm not worried about the ES at all, so that's never been a factor. I just go for the one I like the most. Couple of examples.
JRD Robocop: I think the blues in the regular look better (and suit the subject matter better) than the silver in the variant.
Tyler Stout Akira: again, I think the vibrant colors of the regular look better than the metallic paints in the variant.
Tyler Stout Star Wars (trilogy): I like the variants more on these three. The regs look fantastic, but I think the variants have a mor classic look.
Could probably post a few more examples but that's the gist of it
I suppose it's nice to have a numbered print that has been signed by the artist as well, or even an AP, but the look of the print is pretty much the deciding factor for me.