I've recently used both Raphael and jQuery SVG - and here are my thoughts:
Raphael
PROS: a good starter library, easy to do a LOT of things with SVG quickly. Well written and documented. Lots of examples and Demos. Very extensible architecture. Great with animation.
CONS: is a layer over the actual SVG markup, makes it difficult to do more complex things with SVG - such as grouping (it supports Sets, but not groups). Doesn't do great w/ editing of already existing elements.
jQuery SVG
PROS: a jquery plugin, if you're already using jQuery. Well written and documented. Lots of examples and demos. Supports most SVG elements, allows native access to elements easily
CONS: architecture not as extensible as Raphael. Some things could be better documented (like configure of SVG element). Doesn't do great w/ editing of already existing elements. Relies on SVG semantics for animation - which is not that great.
Conclusion: If you're doing something quick and easy, Raphael is an easy choice. If you're going to do something more complex, I chose to use jQuery SVG because I can manipulate the actual markup significantly easier than with Raphael.