I got the email too but i'm worried about signing up because of the possibility of things not going well
The SOAK is just like the leaks. You need a stock device to install it. In fact I expect the SOAK to be the .217 leak. It uses the stock recovery, is a patch update to the current files on your phone and will fail if you've made changes (removed system files, installed safestrap, etc..).
If you are stock, I would definitely fill out the web form/survey and get it. You'll have the official build at least a week or two before everyone else and be allowed to give your input on their forums.