Well it's a good thing that practitioners of the Indian traditions are not in the majority on RF, or we'd already have 200 posts taking exception to, protesting, or clarifying Maize' descriptions. But trying to describe religions with no official dogma or formal, organized church is problematic. There's little that can be said about the Eastern Religions that actually applies across-the -board.
I've met Jains who eat at McDonalds and polytheistic Buddhists. Hinduism's strict caste system is actually illegal in India.
This being said, I'll throw in my two cents.
The metaphysics and goals of these traditions are essentially the same. All revolve around the concept of enlightenment.
Enlightenment is the "expansion" of the mind to the point of directly perceiving a multi-dimensional quantam Reality. All three traditions aknowledge the impossibility of describing or even approaching any concept of such a Reality from a 3-D perspective.
Hinduism and its Jain and Buddhist offshoots differ in traditions and culture. Hinduism and Jainism are similar enough that Gandhi, for example, was perfectly comfortable with either label.
Buddhism has taken the impossibility of describing an 11-dimensional Universe to a 3-D mind to heart and does not even make the attempt. Traditional Hinduism, on the other side of the coin, is obsessed with trying to describe and depict the ineffable.
Metaphysically, all the Eastern Religions are comparable. Their differences are cosmetic.