Since I gave this such a kicking the first time I tried it with my first toon (Gunslinger), I reckon needed to come back here and finish my slice of humble pie. Just completed this with my Commando with Healer, using the famous running-around-it-in-circles-firing-wildly-technique. 'Worked like a charm. What made me LOL was that after last time, I was all ready for a session of repeatedly dying followed by the let-the-tank-hit-it-while-running-away-and-healing-technique but the bot actually went down quite nicely.
