Probably the best advice here, actually. Try them all and forge an opinion for yourself. That way you'll find what you truly like the most.
... sence we're talking about opinions.. here is mine from more of a customer service side :P
The Majority of people that come here fir the first time usualy don't know enough of what they are looking at to form an opinion that is going to be viable or useful even to themselfs. Asking others that have a well formed opinion will often give those that are new the experiance to be able to know what their looking at.
So Telling people that ask "Whats a good unit frame addon if im cooming X-pearl" to go fk off and look for themselfs is not a good answer. instead telling them to look at ag_UF or PitBull, and THEN telling them to figure it out from there. Just better experiance, IMHO best not to poke people in the eye when you don't have to.
well... this idea is an opinion in most regards, and not one i debate so don't bother responding
While i don't perticularly like "Addon preferances" as a config method, it certainly is functional, slightly intuitive once you get used to it, and does what i want it to. for all intensive purposes it serves my needs.