I would like to try out the new OS4.0a on my SD1. From what I've read, it sounds good, but so does my SD1 with the current OS3.0b installed.

The question I'd like to ask is if I did install OS4.0a, and then wished to revert back to my original 0S3.0b,would this be simply a matter of just reinstalling the OS3 over the OS4? This presumably, would revert my SD1 back to its original status before OS4.

I'd be grateful for any help and advice on this.