Very.

I recently switched from BeautifulSoup to lxml. It's tons faster, and I like it quite a bit more than BeautifulSoup. The documentation isn't quite as good, and it's a bit of a pain to install, but if you have to do a bunch of scraping, I'd check it out.

What pain? I've only used lxml for a project on Windows, but there, it was as simple as installing setuptools and then 'easy-install lxml'.

I think the 'pain' comes when there are issues with the c library that lxml binds to.