For example, which one of these is "more neutral"?
Unless you can find something that is perfectly flat, there will be no "most" neutral speaker. Perfect neutrality is a Platonic Ideal that will never exist in the real world. However, "as neutral as it gets" can be read as "in that group where there are only minor/insignificant variations from perfect neutrality." Not sure of the intent by CleanSound, not being a mind reader, but that's how I read the difference in the two terms.
They both look very neutral to me. If I wanted to pick nits, one of the speakers dips to -2db at one VERY small range of frequencies, but both are +/- 1db everywhere else.
Are there speakers that are +/- 0.5db for their full range? If so, I will be happy to say the LX are
NOT as neutral as you can get.
But I will still say they are as neutral as you can get for the money and level of SPL that can be cleanly produced, with very few other options at that level.