With followup, focus, slash, repeat, I get 3 mins with my claws/sr (no damage aura) and (I think) 1:45 or so with my claws/bio. I really should start a log of those pylon times.
Since claws attacks are low on recharge as it is, I've never thought that going proc-monster would work out too well. I generally stick with AT IO full sets in Followup, 5 Hecatomb + Achilles Heel in Slash and 5 Apocalypse + GladJav proc in Focus.