Can anyone tell me the main advantages of BES v4.2 over BES v4.0

Thanks

different kind of admin role

BES 4.2 isnt out yet, maybe you mean BES 4.1.2? Check the BES forum for more info.

4.1.2 (latest version of BES) has 3 key funcional changes cf. 4.0

1) Revised UI for the BB Manager - takes a while to get used to but much easier to use.

2) Role based usage - give your helpdesk guys access to move/add/change users without giving them the abillity to reboot server.

3) Group based admin - shove your end-users into groups and apply policies to groups etc.