A friend of mine who thinks pleasure is a 50-round box of hot .44 Mag shooting each week went and bought a Raging Bull.
Art, I guess you mean he went out and bought a Raging Bull in .454, not in .44 mag?
I have a .454 Raging Bull, and this round has roughly twice the muzzle energy of a standard .44 mag, but this isn't needed for deer. As Rembrandt points out, the .44 mag is ideal for deer, so to answer your question, it's "better" because it's not overkill (less noise, less recoil, etc.). But OTOH, you could use .45 colt for deer. Either is great. I've had Raging Bulls in both .44 mag and .454 casull, and I kept the casull.
One caveat, though... that residue ring mentioned above, built up after firing shorter rounds.... with .454 casull, it is much more important (imperative) to thoroughly clean that ring out of each cylinder, after shooting .45 colt, before beginning to shoot .454 casull. .454 is an extremely high pressure round, and there is no room for error. Since that ring at the front pinches the case mouth, it causes a stronger grip on the bullet. If the bullet doesn't release as quickly as it's supposed to, it can dramatically raise pressure in the cylinder. At best, this can mean stuck cases, and at worst, catastrophic failure.