I have 1-4, but will pass on 5.
I got them all from amazon, and I really should have returned #1 (despite the huge bath I'd have taken on international postage). The binding was a mess - it came apart as I read it. The other ones were fine but watch out for that. They are pretty huge books so I'd imagine this is a common issue. They are fun as hell to read though - feels like you are reading from the Book of Destiny. You want to stand up and put them on a plinth.
Having said that, I just pre-ordered the IDW Wally Wood Artist Edition book - 22" x 15"! What the fuck! I have no idea what I'm gonna do with it.