it works pretty well. you click on a pdf and you get your choice of viewing it with either the reader program or the lite version of the office thing they have on there.
With the good processor and gig of RAM, it handles them fine. I actually have a scanned book that gives Goodreader on my ipad1 fits (takes a few seconds to flip a page-- it's something goofy with that scanned document. The Nook handles it much better.
That said, you're gonna want to check it out at the store. Bring a document on a microSD or find one you can download online that's like what you want to use. If for no other reason, 7 inch screens stink for PDF (especially skinny ones like this). Print is very small in portrait and you can only fit 1/3 of a page on landscape.
If you really want a good PDF reader, I'd consider a refurb iPad 1 for not much more (I never had any problems with a PDF other than that one) or a bigger android like a Xoom or something (gonna be a lot of deals on those black friday).
To top it off, it looks like the Nook tablet is not gonna be as easy to hack/mod as the color was. Pretty good chance I'm taking mine back unless XDA hits the motherload before my 14 day window closes.