Thanks for the replies everyone!
It seems like the advantage of higher pixel density on the Voyage is negated by the limited customisation on the Kindle.
I suppose that can solved by modifying the e-books but it's not something I'd do.
Unfortunately, it's highly unlikely I'd get to demo them at all in Australia.
It'd be interesting to see the differences with both readers using the same font, size and weight.
LCD pixel density comparison:
http://www.mrgeek.me/wp-content/uplo...-50-to-300.png