First, while you are channeling the skill you have no control over the direction anymore, so your bear will just stupidly run in the original direction until it hits an obstacle or you release the button. This concept might work for Sentinel’s Shieldrush, as the run speed is much faster. But Rampage’s run speed is quite slow, and it feels unnatural to have no control over direction. You also end up by pressing button, releasing button, correcting direction, pressing button, releasing button, correcting direction, pressing button, and so on. Not much fun, especially in the many levels with narrow passages and many obstacles.
Second, every time you release the button to end Rampage the bear will roar or grunt. As this happens quite often, it quickly becomes annoying.
Third, there seems to be bugs in the terrain of many levels that prevents Rampage from working properly. Please see example video “Alpine Halls”. The video also shows desyncing issues.