IBG was my least favorite song off LT from day one, and only got worse from there. Primo is waaaaaaay better. In addition, I love the raw energy the unpolished demo brings. It's similar to why I like GATS, it's unfiltered and emotional. IBG feels so clinical and straightforward, makes me feel ehhh every time I hear it. Also, Primo is much more in line with Linkin Park's "let's try to push the experimentation message." For instance, Primo has two bridges which is pretty different for a mainstream band.
IBG > Primo I still listen to both, tho I usually get bored pretty fast of LPU albums so I'm amazed that Primo is one of the few that stuck by me, but at the same time, I'LL BE GONE was one of my favorites on LT, the rock element is what wins it. Primo is good, but the slow pacing with low energy isn't always my thing.