I'd probably be in jail or killed if I spoke my thoughts. But on the other hand, if I don't talk when it's important I might end up killed... Hmm.... Over all I think that holding my tongue would be better for me, not the most innocent thoughts.
Would you rather: Stop aging but can die from daily things like carcrash, murder, suffocation (Assume you wont get any deadly problems/disease like stroke, cancer etc*.)
Or
Live exactly 800 years but you are unkillable under that time. (You physically age slower, so 400 years is 40 years to people who die at 80)