So got a early flight from STR to FRA and as a LH Senator was directed to the Senator "Comfort Area" in Terminal 3. Its more badged as a Eurowings area than Senator, I entered at 05:05 and for the 55 mins I was inside only 2 other pax entered.

Its essentially a sectioned off area of the terminal with just 1.5m glass partition separating it from the rest of the terminal. On arrival there is a gate guardian who takes your details down and checks your status, Inside there are around 40 seats, both regular with tables or tall desk types overlooking the runway. Views are pretty good to be honest. There are lots of power sockets available.

There is a coffee machine, a fridge with water, juice and soft drinks and a newspaper stand. I was offered a snack bag, and was mildly surprised, at 05:10 to have a cheese sandwich, chocolate bar and pear inside it. I would have preferred a croissant or other pastry at this time of day.

So I think it is absolutely fine to use it to grab a free coffee and sit somewhere with power sockets for a while, but dont expect much more.It might be less tempting during busy times though.

Unless you are HON, then this is the only complimentary lounge option for Senators.