Features:

Unfortunately, Newton chose to write the Principia in Latin in the version we call New Latin---
---which makes it very inaccessible today. In Newton's time, people were finally giving up on New Latin as a practical form of communication. Newton himself gave up on it and wrote his other major book Opticks (1704) in English.
Arguably the Principia is the one of the last great books written in Latin and arguably the greatest book written in Latin in terms of extractable content, NOT style.
The only later great books written in Latin yours truly can think of were those of Carl Linnaeus (1707--1778), the "father of modern taxonomy" (see Wikipedia: Carl Linnaeus bibliography).
Even worse than writing in Latin, Newton chose to write the Principia using a form of geometrical calculus that never caught on---and for good reason---and his contemporaries and near contemporaries (starting probably with Pierre Varignon (1654--1722)) had to do a mathematical translation into the formalism that developed into that of modern mathematics.
Subrahmanyan Chandrasekhar (1910--1995) (Nobel Prize in Physics, 1983) has provided a version of the Principia accessible to the modern person, including the modern physicist: Newton's Principia for the Common Reader (original publication 1995).
And another thing, Newton's age was still using the darned long s = ſ for the lower case S for the beginning and middle of words---note it's ſ, NOT f.