Not being able to get out of the tank sucks, people saying "aww its better that you can't exit tanks, tripwire know what they are doing....blah blah blah" are probably the ones sucking up to get in the early beta, Well, I'm sure you'll realise when you all play it that tanking won't be as much fun as RO1 in the sense of freedom.
The majority of people on this server will want to be able to exit and enter a tank, People buying the game who never played the first and who are probably coming from Battlefield Bad Company 2 will want to be able to exit tanks.
Even exiting the tanks like Ro1, popping out is fine, put a ten second delay or something.