Three out of three people I have asked, with no explanation beyond presenting both images at the same time and asking which they prefer, have pointed to the mock-up with equal-sized lettering.
Two of those people were Japanese, and they said something kind of obvious from which I think a lesson can be drawn: The equal-sized lettering is much easier to read.
If you take any one letter from BT's image, excluding the THE and the OF, and compare it to the corresponding letter from the mock-up I made, BT's letter looks better, no question. However, I still think the fact that it was retro-fitted from having no THE at all to its current state has made it deeply flawed. Otherwise, my highly amateur mock-up shouldn't have been able to even compete with it.
Elmer's latest version is a definite improvement. Besides the larger THE, the II really needed more separation, and now it's got it. If we go with that, I'll basically be satisfied.
However, I would really be interested in seeing more mock-ups made with equal-sized lettering (or at least closer to equal if someone can make that work - I obviously couldn't). I honestly think that if we took that approach with a better font than the one I used, then took the time to add a bit of shading and touch up whatever else by hand, we could get something that has the best of both worlds.
Black Tiger, if you would like to make that kind of mock-up, I'd love to see it.
At this point, I want to see a whole smorgasbord of mock-ups, and in addition to making more of my own, I would like to invite anyone else who has a vision of what this title screen could look like to contribute. After all, if I can make a mock-up, anyone can. You wouldn't need to polish anything - just make sure it fits into 240x32 and uses the same colors from the original.
Here's a blank background and the original image:
Of course, "The Legend of Xanadu II" and "Xanadu - Legend of the Wind II" (dropping or changing the hyphen is fine) are both welcome.