Is one striker better than another? Why would one want a mushroom tipped striker vs. rounded conventional striker?
Depends how you play the striker, personal preference for the most part.
I have been making strikers for years and the personal preference of many callers seems to be the key to which one they want. A lot of folks like the mushroomed tip so they can get more meat on the surface, thinking it would create more friction, actually it just depends on the angle of your striker. I will say this, I have seen top callers using straight tipped strikers, because they can easily kee-kee by transitioning their finger closer to the tip to get that high note. Me.....I like the straight tip.