There are different style manufacture harmonic balancers out there. One style being better than the other? I wouldn't say that, if it does what it's designed to do. Rubber, fluid, or other internal components, as long as it does the job is ok with me. I have the Renntech computer and pulley upgrade on my SRT. I also looked at warranties, support, track record, etc. They have been around a long time doing the Mercedes thing. There were no surprises, However, whoever sells these kits should make available the flywheel locking tool with the kit, or have a core charge to let you use it and return it. Also, if the balancer bolt exceeds a certain length (stretch), the factory service manual requires replacement of that bolt, so include one with the kit. It took a 5 ft bar on the balancer pulley bolt to get it loose. And that same 5 ft bar to tighten the bolt back to the factory spec.