Loading and page turns are exactly the same as for any of the things I have read on the iliad. E-ink in general is noticeably slower than LCD but as I think someone said here recently turning the page of a paper book is no faster.
And regarding your concern about cancelling the order, I think you have 7 days after receiving it to cancel and send it back, at least in some countries (all of Europe?). It might depend on which country you are ordering from.
BTW, I have to say that this PDF looks beautiful to me. I have no idea what it says (it could be instructions on how to get more than 6 items in the iliad contentlister for all I know), but for some reason it seems more pleasing than the a,b,c etc. in most fonts I have seen.