Don't think it is fair to say the Harness on the Apeks is better....If you buy the bp/wing for a Halcyon, or an Apeks, at a dive shop with no one that works there that is highly skilled at custom adjusting the harness to you...or, if you don't know a GUE instructor that can custom adjust it...then, yeah, in this situation, the Halcyon harness NEEDS custom adjustment for most people, and most people can not intuitively figure out how to adjust the Halcyon harness...
Now there are many videos that can get some people dead on, and many quite close.....but ideally, you really need someone that fits these as well as a GUE instructor....The Apeks can be made to fit with a bare minimum of skills...
On the other hand, the Halcyon harness, when fit properly, can be perfect for you for well over 20 years and still be like new....the one i started with in 1997 ( whatever year was the first for Halcyon), is still as good as new.....if it had all the buckles and plastic stuff on it that the Apeks does, it would have been broken several times in the lifetime