I didn't use the RootKit, at least not intentionally. I simply scanned the C-drive. In the old SpybotS&D, many things get queued up, and then processed. It was clear whether there was a problem. Now, there is a very long list of things, each rated with a green bar. Most of mine are rated 2. The answer is no longer clear. If it was a 5-point scale, and say 0 meant 0% chance of a problem while 5 meant 100% chance -- we can then roughly equate 2 to 25% chance of a problem. But there are countless number of line items, each with 25% (on average). Conversely, there are countless items with 75% of being good. If you had 3 independent items, each having 75% of being good, then there is (0.75)^3 x 100% chance of being good. This drops pretty quickly as you increase from 3 items.
I admit, it's an oversimplified model. But the new SpybotS&D really begs the question of how to interpret the output. When should I be worried?
P.S. There doesn't seem to be an obvious way to open up the results again.