Just wanted to give these guys a shout out, I have been using them as my default PDF viewer for about two weeks now. It renders 4 or 5 times faster than Adobe and has all of the features that I need in a reader.
Not sure if it is available on mobile platforms (I still use goodreader as it links nicely to my dropbox where I keep all my gaming pdfs) but I would recommend it for the larger files if any of you are getting tired of waiting for Acrobat to render pages for you.