rising terrain - Australia
I did my initial twin rating years ago in a cougar and empty the thing was lucky to get to get a couple of hundred feet/min climb. However I remember there was no problem in turning either way. Having said that it was common practice to shut down the non-critical engine as the engines were not counter rotated. I never practiced nor had an actual left (critical) engine failure so can't comment on what the performance may have been like in that situation, bitch of thing to taxi though on one engine.
In my opinion with most 'light' twins with fuel and pax to get any ROC is a myth without compromising airspeed which without, you will enter the terrain vertically rather than horizontally.