After Flying the Magister with the stock 1900mah (worthless) then switching to a 3300mah Nimh pack. (Heavy but flyable) I finally followed what Greg did and switched to the Jeti esc and Kokam 3s 3200mah lipo. Wow! This is just what this plane needed. Much more power! Lighter weight! This is now an acceptable flyer. I wouldn't reccomend the lipos to a newbie because of possible damage if you crash, but if you can afford it, go with this setup. Don't waste your money on the Nimh packs, go with lipos.