This was an excellent apartment to stay with our 20 month old son. It was a simple apartment and nothing really to break and Dan provided us a travel cot and high chair. The rooms were large enough that you can choose to have the baby in the bedroom with you or in the lounge. We were there in December, and the heating worked perfectly. No problems with noise as other people have mentioned (unless you sleep in the bathroom which is near a main road) - the double glazed windows did their job well.
There was a fantastic (but expensive) Biomarkt nearby for our groceries (unsure if there were any others). All the central sights are walking distance. If you prefer public transport - U-Bahn, tram stops and airport bus are literally just over the bridge from the apartment. Only word of warning is that the lift only fits 2 people, so even the smallest of strollers would still have to be folded up in order to bring it onto the 5th floor. So one of us would have to take the stroller and the other would take the baby. Not sure how you would work it if you had two children?