Bowhunter Elite, That's the sight I just went to(Impact Cosmic),it's awesome!!
Lonebowman, The Keller I had and my father's also,sounded like a bag of coins rattling when I shot . With the pedilum floating it just rattled a lot(some newer designs I've seen ,I doubt would have this problem...like the Savage). However the Keller was accurate from 0-30 yrds with our bows , mine shooting 232 fps and his shooting 237 fps so it worked.

I know the question wasn't for me but:
IMO pendilums work better on slower bows due to trajectory. The slower the bow ,the more drop you have ,so yardage estimation is more critical.Therefore a pendilum helps eliminate the need to guess yardage under 30 yrds or whatever the pendilum is rated for. Faster bows have a flatter trajectory and much less drop( less critical for yrd estimation). My current bow (for instance)shoots 308 fps and with a 20 yrd fixed pin only drops about 1.5" at 30 yrds on the ground and drops little to none from a tree stand.So in essence I shoot it practically like a pendilum from 0-35 yrds out of a TS . When my setup is shooting 275-290 fps range I shoot my 20 yrd fixed pin like a pendilum from 0 - 30 yrds out of a TS . Shooting bows from 250-270 I have seen friends shoot their 20 yrd pin from 0-30 out of a TS also, but you have to compesate a little(not much though..it just takes a little practice). I hope this answers some of your question. Pendilums are great for some people ,if you like them I think you should get one. Just my $.02 on this subject ! Good luck !!