My experience with fast rate hyd cams is...... The lifters collapse more than "normal" on the opening side, and when the rpm reaches the point where lofting starts to occur, the lifters "pump back up", and if there is any appreciable preload, the valves hang open, and the power drops like a rock.
That's a far more technical explanation than what I was going to say, which was the valve train comes effing unglued beyond a fairly moderate RPM.
I hate those hydraulic Xtreme cams... noisy, sh!tty valve train control at higher RPM... everything I DON'T want with a hydraulic cam. I went to solid lifters years ago and haven't gone back.
