Jim's and Kath place is spacious and clean. You will have two separate rooms with enough space for 4 or even 5 persons. Just remember that you will have to use the stairs (which you probably already know) to get to the third floor.
The house is perfectly located between PVD airport and Downtown Providence, with easy access to Brown University and many wonderful attractions. In addition, there are grocery stores, pharmacies, etc. literally on walking distance. The place has all you need for a short stay, including a fridge (with some awesome complementary local beer in it), a washer and drier, etc.
The hosts are educated and open minded, and willing to help their guests. We really enjoyed our stay in Jim's and Kath's place.