I've never flown a 214B, and my memories of the 61 are foggy at best (haven't touched one since '94) but I seem to remember she didn't like altitude very much. It would come as no surprise to me that as long as the big two-blader had the lungs for it, she'd outperform Big Igor up high.
I do remember a trip across the Canadian Rockies at 11,500 once, speed somewhere around 80KIAS, with 1/rev and 5/rev competing for the rights to shake us to bits....
Maybe some of the loggers could help........