My ipad must be broken, it loads webpages slowly, MUCH slower than my macbook air or any other PC I have. The inital load is slightly slower than on a laptop/desktop, but it's the rendering of the webpage that is significantly slower. On a computer the whole page loads at the same time, but on my ipad only the part of the page viewable loads, you can see this when you scroll down and that part of the page isn't loaded. I've even occasionally had it where I scroll back up and the part of the page that was already loaded wasn't loaded anymore.
I'm not talking about a long time, maybe a second or 3, but its 1-3 seconds that is not present on any of my computers.
And yeah PDF files are slow, especially when you are talking about a 700 page textbook with pictures. Both goodreader (especially goodreader is painfully slow) and iannotate can take several seconds to load a page, and it seems to load them one at a time, but on my computers once the entire PDF is loaded I can cruise thru the entire 700 pages with no loading at all.