most efficient class/spec for upgrading gems

[nalleman]

My Witch Doctor (Pet build) does 28 Rifts regularary, sins his gems are upgraded quit far and gems from chest can be upgraded then it is the best I have so far.
Also have hte problem with my DH (Sentry) that it generates higher rifts than it can survive in and goes on dying in 30+ onces.
my Monk is generally fine for 25-28 rifts aswell by the bot, but its not using spirit generator enough and gets stuck a little to much on trying to spam Aura to be really effective.
Im guessing once geared then condemen/shotgun Crusader will be fine for 30 rifts aswell, currenetly its stuck on around 25 rifts due to it cannot do the trails quick enough