I've never been able to tell a power difference with a stock lightened flywheel.
Take that money and put it towards a good programmable ignition instead (ATP EPIC or ATP FLAME). Now there's a difference you can feel.
Second generation TBM's work with the EPIC's as well. At least it does for me.
IMO, Lightweight flywheels are a finishing touch to a built up engine.
Haven't we been getting mixed reports on that one?
When I bought my 2nd generation TBM (direct from TBM) it was compatible with the Advent. I had two fail with a total of about 4 hours on them. My warranty was denied both times. Now TBM claims they are NOT compatible. After fighting it for 2 years, I finally stepped up to a MSD Total Loss. Took my time with the wiring and install and it has been 99% trouble free, with the only problems being poor quality work from JSS.