We used to have one with a 60" bar. That thing would cut like mad with a new chain- we mostly used it for big stump flares. When it started to go dull it was a real b**ch to get it to cut staright again.
I remember watching P.G. on a 10 ' ladder flopping a giant Willow oak(it wouldn't quite fit into the space provided) with that saw- he was the only one mighty enough to pull off a cut like that.