I was in this lounge (the Louis Tavern) this week before the UA flight. As the TG lounge near gates D1 and D2 doesn't open until 5:00am (or 5:15am), that is why (I was told) they are using this one. The lounge is OK, there are sandwiches, rolls, fruit, etc. The staff is nice. It is a small lounge, but I imagine that lots of passengers don't make it here because of the early (6:00am) departure of the flight. I know that I arrived at the airport a bit closer to flight time than I usually did when the flight was 7:00am.
One difference I noticed is that Louis Tavern had water bottles in the fridge for passengers to take. Remembering to take one and knowing where UA gate security looks for the dangerous booty

allows for a refreshing beverage when I want during the BKK-NRT flight. Then, I refill the empty one (0r 2) in the lounge in NRT for the flight to USA.
I actually like the 6:00am departure. It is a better transition from an evening of good clean fun on the streets of Bangkok.