I started SB a few months ago and joined their website as part of a good introductory offer (one month + the supercharged book). I was unfamiliar with the plan and thought it was a good idea.
For those just starting SB, their daily menu suggestions can be very helpful. The boards are very friendly w/o much of the usual snarkiness found on some other commercial diet boards. The boards are pretty much self moderated. I've grown close to the 100+ group and continue to post there.
The weight loss tools can be found here and on a lot of other free sites. Same goes for many of the recipes. The main con is that it is probably the most user-unfriendly site I've ever used with many continual bugs.
If you wanted to check it out, just read the fine print and be aware of your join date and if it's not for you, then you can always cancel. HTH