Vintage Channel is an extremely unique plug in due to the crazy routing section and various other stuff. There are quite a few things it can do that the new plugs cannot. Craig has mentioned this and some of the things he does in the X1 Advanced vids aren't really possible with the new stuff or at least not without some very elaborate setup. If you have X1 unboxed it came with that as well or you could just redownload whatever version you need to access it from your account (if it's not there because you bought a retail copy I think support will send you download links). Also you could see if it is included in the custom install section of X3 as I mentioned earlier.
As far as R-Mix I think that is a very useful plug and definitely worth installing. It's one of the main reasons I bought X2. Unless of course you have a fancier plug like Izotope RX or something but even then I don't think even that has the creative possibilities in R-Mix via automating the square/circle thingie/faders.