The Adina at the Hackescher Markt was well located, very spacious (including a kitchen and table to eat at) and offered lovely views from its balcony. It also offered good, free wi-fi and a nice breakfast. I would stay there again in a heartbeat.
I only had one small complaint. They have a nice restaurant with a good menu (they actually have some healthy options, which I haven't seen much of in Germany), but if you want to eat dinner there, your only options are to eat in the drinks area, which means you have to hunch over a knee-high coffee table, or out in the lobby, which is brightly lit and doesn't feel remotely like a dining area. We were eager to eat dinner there, but didn't like either option, so we always ended up looking elsewhere. It's a shame.