Post-Visit report: It was OK+.
Large, spacious hotel that was largely empty (Breakfast room was not busy at all despite having enough food for thousands!)
Upgrades are not great, was given a small renovated king room with two twins pushed together for a 'king'. I was surprised since I contacted them in advance, and the online inventory showed numerous suites available, now obviously, not a part of their upgrade inventory
The location is not great, unless you are working in the defense industry or traveling by Taxi everywhere. Bus connections are available, and it's about 15-20 min walk from Potsdamer Platz.
Staff are friendly and numerous in case you need anything. Lounge was smallish, but well stocked for snacks at 5pm, Beer and wine available by order.
Price was right this time, but for future meetings I'm not sure.
All in all, OK, but not amazing.