When I stayed at Tyson's corner, I took a cab from DCA (Reagan) to the hotel. I arrived late in the evening and it took about 20-25 minutes. Of course, there was no traffic.
On the way back to DCA, I took the train. It was a LOT cheaper and not a hassle at all. It took only a couple more minutes than the cab at 11pm and when I looked down at the highway from the train, there was lots of traffic. A cab would have been a horrible idea. Plus, the train was quite enjoyable and easy to figure out for a first time DC-rider.
So, you really should be taking the *time of day* into consideration when you choose your method of travel.
It seemed to be in a safe neighborhood. There are a lot of high end car dealerships close by (Ferrari, Maserati, Bentley, etc) so I think you would be ok leaving a uhaul. They had plenty of parking for one. The walk to the metro is maybe 4-5 minutes (you can see the hotel from the metro stop).