its true that many A ranks/B ranks and even S ranks are crap when compared to other suits of lower class...
A rank fail suits
Zeta, ZZ, The-O, Duel, Aegis, Buster, Perfect Gundam, Big Zam, Full Armor Gundam, Scissor Astray (the new funnel one), Strike(dagger), Aile Strike, GP-03 Stamen, Hamma hamma
Potentially good suits: Shining gundam, G-3 Gundam
It would take me too long to list the B rank fail suits so... =/ Anyways.... this list is just from my 210kexp of playing gundam TW... many people would probably disagree but from what I can see from experience, those are the feeders and pointgivers =)
Though there are a few select maps of which some of those suits may be good in, for the most part they are just incredibly useless. Plus, if everyone had the same opinion as me, it wouldnt be fun to see the same suits being used over and over again =)