Hey RichJB, it's good to have a photo chopper on board :^)
I use the method you described a lot because it does give you more control. I also make adjustments using masks and curves. All the methods mentioned so far can be used for various results. No one method will work best for every photo(landscape versus portrait-daylight versus night), so it's best to try and use more than one. That's the beauty, and curse of photoshop, there's more than one way to do things. However the more control you have over an adjustment the better.
Although I miss working in the darkroom, digital gives me soooo much more control over my B&W shots then film ever did. Not to mention my clothes don't mysteriously get holes from the splashing chemicals :^) There are still some film techniques that can't be matched by digital but even then it's still scanned and played with digitally.
I don't like using automatic filters like SilverFx because I want total control over the final image. I haven't really found a one click solution yet.