In my experience Hartle is easier and more engaging. It also relies on at most two years of undergrad math for non-math majors. Spivak, while fascinating, is a much more advanced book. Again, it is great for math majors, but there are much gentler ways to learn diff. forms and topology for a physicist.
I read my way through Schutz with relative (!) ease. Do you know how they compare?
Anyway right now I’m studying the math. Wandering through Spivak.
In my experience Hartle is easier and more engaging. It also relies on at most two years of undergrad math for non-math majors. Spivak, while fascinating, is a much more advanced book. Again, it is great for math majors, but there are much gentler ways to learn diff. forms and topology for a physicist.