You'd think from the name that the hotel was actually at the Potsdamer Platz, but its over 1km away. They've taken a leaf out of Ryan Air's book in terms of creative geography i think. Not the end of the world - its only a 10/15 min walk, but something to be aware of. The room was very basic (as expected, so no disappointment there), and spotlessly clean. The staff were very friendly and helpful.
But for anyone travelling for business, the advertised "hi-speed internet" is slower than the 56k dial-up I had as a kid. Its absolutely useless. I struggled to send even a basic email in less than 2 minutes, and you can forget about downloading any attachments. Choosing this hotel meant I was completely unproductive for two days. If you have any need to work during your stay in Berlin, I'd recommend you look somewhere else.