The first few games in the series were phenomenal, especially considering that most anime games usually aren't that great.
However, things went downhill when Generations was released. Whilst I didn't necessarily mind the gameplay changes, the games started to become the same as its predecessor with little changes. For example, Storm 3 is basically Generations with a story mode, and many features/missions/characters were taken out to compensate for that. As a result, it is losing all of the elements that made Storm fun to play.
I remember playing Storm 1 and Storm 2 for over 30 hours, but I finished Storm 3 in less than 10. I have barely played it again, since it's become stale to me. The framerate drop and support type glitch don't make it very enjoyable either, not to mention the loss of a combo that makes combat even more repetitive than it already was.