Tried it and yes it's good time saver if you don't want to fiddle around and experiment, but almost everything it can do can also be done on Photoshop CS4, Camera RAW 5.0 or Lightroom 2 pretty much free. I do think if your workflow needs to generate plenty of B&W quickly, like wedding/portrait shooters, it is an invaluable tool.
With regards to B&W, whether digital or film, getting the exposure you want right is an important first step. I find digital conversion offers much more precise, repeatable and consistent results, and it doesn't really matter if one shoots RAW or high quality jpeg. Obviously RAW is preferred for the greater colour depth and slightly higher dynamic range.
With film, to get the nice exhibition quality images with excellent tonality and grain, one needs to master the 3 areas of exposure, developing and printing. Merely shooting B&W film and sending them to a lab for developing and printing is pretty much a game of chance.
Obviously a well printed B&W image will almost always outdo the inkjet print but in the bigger scheme of things, you'll likely get quicker keepers with the digital monochrome approach.