After buying the English VN from Mangagamer back in August I have finally finished everything. That's not to say it's long; it's more of a struggle to keep reading the extremely dull text.
Honestly, I think the anime of Shuffle! was much better than the VN. The characters in the anime were far more interesting, in particular Kaede. Also, once you've chosen your "target" girl in the VN the rest basically become background characters. Whereas in the anime they kept going back and forth between each character which felt like everyone was still included in the story.
Each story is included in some form in the anime, apart from Primula. She is almost a totally different personality in the VN if you pick her route.
Sias' main story involves you discovering reverse Sia (her split personality twin sister) and persuading them both to share the same body. Her story was probably the most interesting out of them all.
Nerines' story is about her sister Lycoris, something about sacrificing herself or some crap like that. Nerine chooses to fulfill Lycoris last wish but ends up falling for Rin.
Kaede is extremely tame in the VN. One of the best parts of Shuffle! was her Yandere personality. In the VN she is reduced to what is effectively Rins' servant.
Asas' story is pretty much the anime story. Asa doesn't want to use magic, Rin goes emo to force her to use magic, the day is saved.
Primulas' story is rather... wrong. She becomes extremely annoying with her continual repetition of "onii-chan".
Honestly I'm not impressed with the Suffle! visual novel; not Manga Gamers translation or anything, but the actual content of the "game". The only reason I can think of for wanting to "play" (I think endure might be better here) this after seeing the anime is A) you are curious about the original source material, B) you want some pr0n, in which case why spend hours going through the text. I picked A), I swear.