I have tried a Grado Sonata and Shelter 501 on my 9 sig, while 95% of the time they both sounded incredible, I could never get rid of IGD and mistracking at high amplitude/frequency peaks. I used a Mint and OCD'ed on alignment and tracking force to no avail. So, VPI agrees that these carts are not compatible with the 9" arms due to less mass, but are fine with the 10" arms. I would just like to find something that "works".