Nojo, I wouldn't go so far as to say that they don't make a difference, exposing metal in the right places (generally as much as possible) can really help wheels (Screw Pisces is a good example, comparing my testing to others with different CW's). It's pretty obviious visually, if you're going to have plastic protruding over vulcans sloped parts, or sitting ahead of it's, uhh, smashy parts (Aquila is an example of that), that it's going to lose recoil/smash.
However, Longsword: It's obvious from it's shape and weight that it's not going to work for defense. And just look at it, generally, good attack wheels have bumps, expose the metal on certain wheels, or provide some kind of upper, in destabilisers. Byxis does none of these.
I guarantee Ray Byxis 85 RF will not win a battle against Earth Aquario 230CS, Ray isn't really top tier, and low attack types (except for maybe MLD) don't really work against 230. Also, Ray doesn't need a metal face, it doesn't have enough recoil to warrant it, it makes it WORSE, by slowing it down.
As for Vulcan, exposing the right amount of metal is key, and Horuseus is fine. Honestly, Pyxis doesn't work. I've considered it before, but yeah, Horuseus is better.
The only other attack wheel that's worth using (judging solely from my testing) is screw, and nope, pyxis doesn't work there, Pisces is the best I've found so far