I've been using Aurora, Terry, Elena, and Jessica purely because they're my favorite DQ characters of the bunch. I like Yangus a lot, but he's a bit too slow for me. I'll give him another chance later probably. The party has worked well but I sorta feel like I should replace Alena, as much as I don't want to. She's really fun to play as, but maybe Maya or Bianca would compliment the party better. I'd totally drop Aurora if I could.
I think SE made some great choices with their DQ vets. I maybe would have liked Cannock or Moonbrook, but I get that I-III didn't have much characterization to go on. The only glaring omission to me is Torneko.