It's decent, given a bit slow with standard 55 SoA / SoJ monk. Siege ice golems make it worth it, atleast for me since they can't be knocked down.
The most valuable thing i've gotten there is tomes :P But the guy above me is right about if you specially want to farm imps.
I prefer fire imps over ice imps anyday tho, 330hp ritualist makes short work of them
