I was given an upgrade to this Tower Deluxe room about a year ago, but frankly hardly noticed the extra square footage. I *DID* notice the extra walking to get to and from the casino or the Strip. I didn't think it was really worth it.
Incidentally, I've found checkin at the Bellagio to be much slower than at other hotels, even other hotels owned by MGM Mirage. For example, MGM Grand offers very fast checkin at McCarran Airport and you even get your room keys at the airport. Monte Carlo and TI are also much faster than Bellagio. Luxor is the only one that's worse for checkin.