Re: convert pdf -> with mixture of pages & spreads

> When I run them through "convert" these 2-page-spreads are getting
> compressed horizontally into a single 8.5x11 portrait page.

I could not verify this behaviour. I have just converted a PDF 
containing a mixture of DIN A4 and DIN A3 pages (which is Europe's 
equivalent to the US formats you mentioned) and the JPEGs of the larger 
DIN A3 pages have exactly double the pixels of those of the smaller DIN 
A4 pages.

> I assume that convert is seeing the 8.5x11 size on the first page and
> is making all subsequent pages fit that size.

Actually, ImageMagick does see nothing directly, as it uses GhostScript 
as the delegate for PDF. I am using GPL GhostSrcipt 8.70.

Possibly, this behaviour has something to do with your PDF input files. 
Could place a smaller one somewhere where I can download it?

Greetings from Germany
Wolfgang Hugemann