And we're back.
Flew to Berlin from Bristol on Monday and back yesterday. Flight times meant we had two full days plus a few hours for a quick wander on the Monday and Thursday.
Really enjoyed it as did my wife, so thank you all your help.
We booked through Expedia, flew with Easyjet and stayed in Frederics serviced apartments (thank you
@ClaireSaud for the self catering idea, I recognise your avatar now too!) in Hackescher Markt, which was superb. Hackescher was about 30mins train from Schonefeld airport. We had a hearty breakfast each day in the apartment which basically saw us through to our evening meal which we had in one of the restaurants in the square by the Hackescher train station.
Transport was fabulous, we got a visitor card which covered us for the time we were there and jumped on and off various S trains, U trains and trams, zipping around the city to Friedrichstadt, Alexanderplatz, Potsdamer and so on and basically just having a mooch around. Soooooo many bikes and sooooo little congestion that you'd almost think there was some correlation.
So we went to the TV tower which was ok, the view was fabulous, although unfortunately it was raining that day, but the queue for getting through the security check must have taken about 45 minutes. We went and had a look at the Gendarmenmarkt, Reichstag, Brandenburg Gate, Memorial to the Murdered Jews, Topography of Terror, Checkpoint Charlie and various bits and bobs that we wandered past on our way round. The only museum we went in was the Topography of Terror which we spent an hour or two at but frankly with the amount of information that was there you could have easily spent all day and I would imagine that would be the same at many of the others.
Just around the corner from our apartment was a place called Curry61 which is a hole in the wall type cafe which apparently serves the best currywurst in Berlin, judging by the pemanent queue along the street for it it would appear that this reputation is not unfounded, and it was blooming gorgeous. According to my wife who's been to Germany on a number of occasions and sampled various currywursts this was head and shoulders above the rest

Anyway, fabulous place, loved the transport, fascinating history, too much to take in in just a couple of days, I'd be happy to go again.