My problem with the Storm is the lack of custom fits.
I figured that the Grand Maestro was the next best thing.
A number of reviewers even prefer the GM to Storm.
Personally, I prefer the GM to Storm, but that's based on my "on-the-go" listening preferences.
They’re very different sounding IEMs and are tuned for different purposes. It’s not really an apples to apples comparison, I definitely prefer GM myself but that’s because at the end of the day I don’t appreciate what Storm is aiming to achieve enough to warrant owning one.