I haven't submitted any sites to them yet, but I checked the back links of some sites already listed in the B-Central directory and about half were showing up in Google. I would recommend it, if you category has at least a PR of 3. You will also be getting a link from a highly relevant category, which is good for linkpop. We plan to use this for our more competetive clients.
I do awful with MSN for my main website - ever since they switched away from paid Inktomi listings - if I could pay BCentral 50 bucks to have some URLs actually rank well w/ them that would definitely be worth it.