[hjrosasq]

Well, I had to made a similar choice not long ago, and although I agree 100% with GEli, I have to say that I prefer to have it than don't; anyway, both systems are very good, you should feel them both in your hands, first, that feature shouldn't make a huge difference, since you will have dust anyway, and more or less often, you'll have to clean it manually or send it to service, there're a lot of other features to pay more attention to, but bottom line, is the one that feels 'right' for you.

Good luck!