Well no matter what context, I can't really say who's is better out of Jon or Richie's. Their voices suit different types of music. OK, Richie has sung a number of Bon Jovi songs on solo tours and they sound good but I couldn't replace Jon with Richie in the band. And there's no way I could imagine Jon singing any of Richies solo material.

But if you're talking live, then these days I would say, while Jon's voice is sadly much weaker that say pre-1996, Richie's voice still holds up.