solo?

[Quark]

They are especially gimped in being unable to wear most inferno equipment (always level 59.)

Huh? My level 60 monk's best buddy very much is a L60 enchantress. (Although the other two followers, whom I haven't been using at all, are both L59 right now.) Are you sure about this?

They have some sort of catchup mechanic in that they'll gain experience to one level below you (or just automatically be one level below you?) really quickly, even when not with you. For your current level, I think only the follower with you is gaining experience (my Templar is now 60, Enchantress has some experience towards 60, and Scoundrel has none).