We felt that the most attractive thing of Lisa's Apt. is very close to the train and bus station, close to hot visiting spots. We arrived at the noon by train, walked 10 minutes to her apt., and dropped our luggages there. Then, at the early afternoon already showed up at the Ufiizi and Ponte Vecchio. Plus a neat bedroom and clean bathroom for ourselfs.
By the way, climbing to 4th FL was not too difficult(we both are retired) as long as you see it as your aerobic exercise. Strongly recommend.