Apart form new vs vintage, the TR is a very very different beast from the DR. The DR is of much lower wattage and sags due to the tube rectifier (combined with it's small wattage). It's apples and oranges IMO.
Moreover, do a search in this forum for 'deluxe rever reissue dissapointment problems issues speaker' etc. You'll find lots of threads full of people complaining about the DRRIs needing costly upgrades (mainly speaker and tubes) to sound nice.
Do a similar search for vintage twin reverbs, all you'll get is malfunction threads.
You know your twin sounds great, you don't know how the DR will sound.
My advice is to not sell the twin before making 101% sure you don't need it anymore (ie if it's collecting dust for months because of your new DRRI!).