With a potential RMS problem, should anyone be the second or third owner of a 996?

 

Absolutely! There is a ton of info on RMS (on here, renntech, PCA, etc.). Arm yourself with knowledge, have the car checked out before you buy and have some fun. You'll probably want a lightweight flywheel right away anyway. You can have a new RMS installed at the same time.

 

what's the advantage to a lightweight fly wheel for those of us that don't track our cars? also, do they chatter a lot more?

 

There are two advantages that I know of. First, overall weight reduction, If you've done exhaust system, wheels, and maybe battery to reduce weight, here's another (albeit expensive) way to take off another 40 lbs.

The more noticable advantage is a reduction in rotational mass so the engine revs (up and down) more freely. The butt-dyno says it adds a lot. As far as gear chatter goes, it varies depending upon the kit. To me, it's barely noticable.

 

Engine gains and loses revs more quickly but on the downside low rpm driveability suffers, especially in parking maneuvers or at full lock when the power steering pump is straining the engine, you will have a much increased tendency for the car to want to stall out not having the rotational mass to keep the engine spinning.
As far as the RMS goes, porsche is on their 3rd or 4th different design rear main seal for this engine and they seem to have gotten it a lot better.