Excellent place - it's spacious, quiet, and clean. Grocery and ATM across the street, Mosaik cafe has excellent value for a crowd (meat plate + some veggies will fill a family of 4 for 2-3 days).
Subway is 2 blocks away. Explore the Prater and Hundertwasser within walking distance.
AND Michael is a) super responsive; b) stocks excellent coffee!