It takes some getting used to, that's for sure.

The language it contains was meant to maximize understanding of nuance so it's not necessarily flowery prose or easy to read.

The material itself doesn't take too long to get through.

After contending with the vocabulary, trying to piece together the cosmological perspective that it offers is the first big challenge.

That's a big challenge because to make sense of it requires a lot of other research. I'm just now in my "junior year" of studying that material and, at this point, I think if I made my research my full time job, your 7 year estimate is in the range of reality. I could imagine it taking me that long to read through it all, digest it, distill insights, and write about it all.