I want to upgrade, but...
I currently get the FiOS Double Play Ultimate HD + 35M/35M plan for $105 (which is a sick promo rate, but it's locked in until August 2013).
To upgrade to 75M/35M, the rate would go up to $140 and I'd lose my promo rate.
So I'm sticking with 35M/35M for now.
I might wind up buying a SiliconDust HDHomeRun Prime, sending back the FiOS DVR and switching to CableCARD. That way I'd be able to justify upgrading to 75M/35M a little better.