So I've been here since 10 years back and recently was reunited with LM Bangkok for an extended stay, thus I can say with confidence that the row of tables nearest the stairs to the Mezzanine would be where you want to have breakfast. Morning sun just lays so gently onto you, kinda boosts you up better than coffee. And if you need an illy to go, Khun Kim would be there. He goes the extra mile to make one feel assured before that trip to the office. Have a chat with him. :)
Khun Phai is also wonderful. Bubbly and confident in her goofy glasses, very chic. Team there provides a good experience.