I also use RNOpdf in Vamp, it works fine for me (Is slow on large documents, but i think this is to be expected due to limited cpu power?) except for one detail, when view mode is set to fullscreen and then i zoom into the document, when the document comes back to its normal size the zoomed document still shows (freezed in the last position) in the borders of the screen. I don't know if I explained the issue very well, my english is limited
Best regards and thanks for this up to date pdf reader btw