An update on my exepriences with this. The last few updates seem to have ironed out the bugs. It's now a superb, rock-solid package that loads faster than Adobe's. It's simple and it works.
Only downside is it's too simple. The (only) features I miss from Acrobat are zoom and rotate, the latter being useful when you want to view on screen a PDF meant to be printed in landscape.
Looks very powerful but I found the interface a little unintuitive.
Worst thing for me was the lack of a preview pane. Having to double-click to read every message is the only reason I've decided not to stick with this software.
I am a Free member 
PDF Browser Plugin
Only downside is it's too simple. The (only) features I miss from Acrobat are zoom and rotate, the latter being useful when you want to view on screen a PDF meant to be printed in landscape.
MT-NewsWatcher X
Worst thing for me was the lack of a preview pane. Having to double-click to read every message is the only reason I've decided not to stick with this software.
PDF Browser Plugin