Question:
It takes me a long time to say birkas avos with kavanah, must I also say birkas modim bekavanah.
Answer:
It is sufficient in birkas modim just to imagine you are standing in front of a king (shechinah).
Sources:
Rambam Tefillah 4:15 & 10:1, Chidushey Reb Chaim Halevy Soloveitchick