I'm just getting into this game again, and in rereading the AoD rules, three factions have special faction abilities, and the ones for Clan Jade Falcon seem quite good. Zellbrigen (bonus against elite units, but you have to finish off said elite unit before you move on) and Enhanced Imaging (chance that hindering terrain doesn't imact your attacks) seem OK, but merciless seems really killer! You get to add 1d6 to your Death From Above damage, and you take less damage yourself!!

Does that mean the CJF units in general are kind of sucky, to make up for these bonuses? Why don't all factions have bonuses like these? I just picked up a bunch of CJF units from ebay, but am worried they're going to be tough to fight against with all the DFA'ing they're going to do!

Do you play with these abilities? Why or why not?

Faction abilities were a failed experiment on Wizkids part. They granted faction abilities to three factions, and the point cost of those units do in fact take that into consideration. So point for point, those units are weaker than others because they have these extra abilities tacked on.
At some point Wizkids decided this was unfair to give these bonuses to some factions but not others, and retconning abilities/prices to other factions was going to be a nightmare, so they introduced faction prides.
I think they did away with the faction abilities in Domination....so Domination or later units do not get to use the faction abilities, while pre-domination units do. So AOD/Firepower/Annihilation units have faction abilities, while Domination/Vanguard/Wolfstrike do not.
So Liao and Jade Falcons can be a little confusing to build and play as you are dealing with faction abilities on some units, but not for others.

You could of course house rule the faction abilities to apply to all units, but post dominion units would actually be slightly stronger for their cost that way.

Merciless was included as a faction pride in vanguard. So were some of Liao's abililities.

Oh boy, what a bummer to have picked Jade Falcon as one of my factions to collect...! I can't imagine I'll play with enough forethought to separate out the 'mechs that should get the faction bonuses, and those that shouldn't. Even so, what a pain to try to explain this to whomever I get to play with. What do others do for houserules? I think I may have to post this question in the faction section, and see what others say...

Thanks for your reply

no you would be mistaken in that assumption all house liao, clan sea fox and clan jade falcon units still retain thier faction abilities the faction pride cards were referring to gunslingers recruited to those factions.