The only useful advent capital ships for late game really are Radiance and Halcyon....
Radiance has detonate AM, one of the slickest abilities in the game and one of the most useful for dealing with titans and caps (something you see a lot of late game)...cleansing brilliance is just an added focus fire bonus, and in a stage where frigates are mostly obsolete having good focus fire on a cap is actually quite important....
Halcyon has TK push, which is your best counter for dealing with bomber spam....energy aura is a nice bonus too but it's really the SC and anti-SC capabilities of this ship that are your strength late game...
The other 4 ships just aren't all that impressive late game...
Progenitor has good early and mid-game abilities, but unfortunately those wane in utility late game...malice banks on large clusters of packed ships, and when frigates are obsolete well you won't really be getting much out of that...it is true that you may see corvette swarms but ironically that's where the max target cap hurts you the most...not totally useless but it requires the prog to be in the thick of things, which isn't good at that stage (especially for an extremely slow ship)....shield regeneration just loses it's umph when the greatest threat to advent late game is shield bypassing phase missiles...the only truly nice ability is resurrection, but that of course does you no good if you lose the prog....
Rapture has similar problems....vertigo and domination are two abilities that really bank on having lots of frigates around...again, yes vertigo helps against corvettes but like the prog you are dealing with swarms of ships that move fast and are spread out...not conducive to using a cap AoE...concentration aura is pretty useless too, mainly because players are often forced to break up carriers...if you are able to repulse any enemy titans away from your carriers, then I suppose you could cluster them around the rapture, but that's a pretty risky strategy in my opinion...vengeance would be useful if the percentages were a lot higher...but they aren't, so it isn't that useful of an ability at any stage...
Revelation is, well, obviously useless....
Discordia suffers same problems as the prog and rapture...while it's abilities are nice, they require the Discordia to be in the thick of things (not a good place for a fragile capital ship)...probably better than the other 2 ships for dealing with corvette spam...
What it really comes down to is the fact that detonate antimatter and TK push are the 2 essentials for dealing with late game threats: caps, titans, SBs, and bomber spams...
Malice, vertigo, and the Discordia abilities would be useful for dealing with corvette swarms, but honestly fighter spam or repulsion will go a hell of a lot farther in dealing with corvettes....