I've used all three, Magic Carpet, Thumbillow and Thumb Straight.
I don't use any of them now (converted to two-hand mostly, although I do still throw one-handed using different equipment) ... what finally got me in a good spot was changing thumb sizes and pitches. Here's how I'd rank them...
1. Magic Carpet
Pluses: Good quality adhesive, works within a wider range of applications, economical.
Minuses: Will irritate the thumb skin for some people, pinch it a little bit and you will hang up badly
Verdict: Works well and hardly ever wears out, but isn't for everyone
2. Thumbillow
Pluses: Most comfortable by far, doesn't really change the base feel of the ball
Minuses: Isn't durable, isn't available anymore (that I know of)
Verdict: Would probably be tops but I'd hate to get used to using this stuff and not be able to buy it anymore
3. Thumb Straight
Pluses: Pretty durable material, no adhesive necessary
Minuses: Sometimes you have to open up a hole further to install it, easily damaged while removing (and tough to remove; I had to use needle-nose pliers), can be tricky to get it aligned, thumb holes drilled to different depths will cause issues in regards to consistent use
Verdict: Essentially creates a "double pitch" in the thumb hole, meaning the pitch at the base of the thumb and then an exaggerated pitch at the tip. Has the effect of adding additional reverse; it's supposed to promote flattening the thumb but it didn't work for me, and the material is somewhat tacky. I probably wouldn't use it again.
Jess
