After looking at a couple two-column scientific papers on the Mini, I'd give it a thumbs up, but maybe with a caveat: a good pdf reader makes a difference.
I'm using GoodReader (which I just bought, so I'm still on the learning curve), and it has a global "crop" command that is quite useful. You can set this for all pages, or odd-even pages separately, and it'll crop the borders, making the difference between a full page being either difficult or comfortable to read.
If you read in landscape mode, and don't mind a quick flip to go from top to bottom of page as you transition columns, then you're good to go from the start with no zooming needed.
Then, when you do hit that graph that has way too much data, you'll just have to zoom in.
Regards,
Tom