This was our favorite place to stay on a five-week Euro trip, an amazingly bright, clean space with smart everything in a great neighborhood just a 20-minute walk from Potsdamer Platz as well as tons of museums and other tourist sites.
Seriously, these guys have thought of everything: self-check in was a breeze, as was finding the place, and we were blown away by the interior.
It's got floor heating, automatic blinds, a great kitchen set-up that's fully stocked with everything you'd need to cook, including complimentary coffee and so forth. A super comfy bed with plenty of toasty comforters and a small balcony overlooking the square below, and it also has a great living room space with sleek, but comfortable furniture, and a big table for working-vacation types. It's a bit pricey, but you get what you pay for in this instance.
10/10 would stay again!