Concerning your question re the seat: It has a movable privacy screen, which turns the seat into a semi-suite and shields the upper part of your body.
You will also experience one of the largest bathrooms in the sky and can get freshly made scrambles eggs, if it tickles your fancy.
Concerning your lounge question: LH SEN and F lounges do not even remotely play in the same league, probably not even the same sport.
The F lounge has a restaurant a-la-carte section, a choice of champagnes, bathtubs and rubber ducks, personal assistants etc. -- a completely different planet from what the SEN lounges many Germans call the Kartoffelsalatparadies (potato salad paradise), because of the self-serve mediocre food there.
Enjoy!