User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-98.192.166.156-20130309055628/@comment-1758220-20130309164313

What was broken about it in Tri was that once you filled up your spirit bar fully, it would not decrease at all when you used spirit slashes, and would only decrease after an extended period of time of not using it. So essentially, you'd get it within the first 10 seconds of the battle and then never lose it, so your attacks were super powerful and you could just spam spirit blade over and over again.

In MHP3/MH3U, each tap of the R button decreases the spirit bar, even when fully filled. Not to mention the red and yellow levels drain faster as well.