Yeah i think the bonus stuff is the most interesting on the collections, but the alternate mixes are worth checking out sometime.
I just found out about "Greasy Love Songs". Its about time Ruben & The Jets got a proper release with the original mix as well. I know everyone doesn't give a shit about that album but it is honestly one of my favorites from them. It kind of reminds me of the Beach Boys 'Wild Honey' era, I guess the influences are very similar (R&B and doo wop).