I did a sub-i. Very good daily teaching, friendly attendings/residents. Since you use vsas, it's straightforward, BUT you NEED to call the medicine clerkship office to see what they actually have available. I was waiting for like a month to get confirmation, so I called gwu, they told me what they had open, and I had to go into vsas to change my rotation from one specialty to another, because the initial one--cardio was full...but was instantly approved after that.
The actual on boarding to get an id and access wasn't bad, the computer training wasn't either...they use citrix and all scripts I think. Gwu is 20ft from the metro, DC is HOT in the summer, you'll be there 10-12h/d. Free lunch usually. 9/10 experience, got a strong letter of rec from my attending. Matched higher than I ranked them, but it was a good experience.