In addition to talking to John about NVSR, there is a ton of excellent and thorough DD on this board, starting with the ibox/intro. Certain individual posters have also done helpful DD. Some of these are river, stockfly, arpj1944, and aliangel. I'm sorry if I'm missing anyone but in reading the DD of those mentioned, other people's DD will surely pop up.
From my perspective, NVSR management has all the bases covered. Just sayin'.
IMO, only.