I've been using both DBoost and Renicer, and both seem to give my old girl (B&W G3 with G4/500 CPU upgrade, OS X 10.3.9) at least a bit of a boost without necessarily turning it into a rocket.

And from the speed with which MS Word just opened tonight, when I gave the latest version of Renicer a try after using DBoost for a while (OK, I'm indecisive!), I think I'll be sticking with this app for now. There was definitely a bit of a zing happening.

A couple of minor gripes. First, I really think developers would be doing themselves a favour if they posted on VT what's changed in their latest version. It's not here, it doesn't seem to be on the developer's website, and it certainly ain't in the manual (still dated 2002 -- gripe no. 2!).

Otherwise, this seems to be a pretty solid little package. And according to my 60-second observation test using Cunning Fox (no, not very scientific, but what do you want for nothing?), Renicer uses only around 18 MB RAM, and between 0 and 4.1% CPU in the background, according to Cunning Fox. By comparison, DBoost uses 27 MB of RAM and up to 5.5% CPU in the background, and seems more busy in terms of CPU activity overall. OK, not huge differences, but differences nonetheless.