What features if any do you lose if you move from NotifyLink to BES and GMS?

We have used NotifyLink for a few years and are quite happy with it but our management wants us to evaluate BES and GMS.

We brought up a BES server and a couple of things that we noticed (or maybe we have not figured out):

1) There is not a way to read something on the Blackberry and not have it marked read in GroupWise.

2) There is not a way to do a look up an address if it's not in your address book.

Does anyone know of a way to do this?

Are these features available in GMS?