To add my experience here on the lounges, I initially used the Aeroflot Galaxy lounge at Terminal E. It was actually not too bad, quite a number of seating. Food selection was ok - with 4 different hot dishes (2 type of porridge, 1 egg and 1 sausage).
Later I moved over to the Mastercard lounge (first time ever using a Credit card lounge) and indeed, from design point, it was very nicely designed. [received a New Year gift of a luggage cover]. I did had to sign a form (not sure if this was normal - but was told it is just for administration).
The lounge was very packed, although I did manage to find a small table for 2. I found the breakfast options good and service was fast (including the food delivery).
The buffet selections were also good.
Based on my one time experience - I would say this is a nice lounge to come indeed for the food and beverage, but for relaxation, the Aeroflot lounge was better.
Cheers!