I was using the LPI on my Technics SP10. The difference it made compared to my TTW weights was not subtle. It brought a level of clarity to playback that was prevously missing. It's expensive, but IMHO, worth the investment.
I say "was" above, because I recently replaced the standard SP10 platter with a newly developed copper/gunmetal unit from Artisan Fidelity. With the new platter, the LPI did not contribute anything over my Kuzma Strobi or standard Artisan Fidelity weight.