The level flight of the aircraft depends on fuel, ammunition (C.G moves slightly), speed, altitude etc. Stop complaining about level flight and learn how to trim your aircraft. The aircraft, even the noobiesfire, do not fly alone.
Sometimes time i think the guys would like to take off, put the legs above the table, the hands behind the head and then light a cigarrete and smoke while the aircraft flies... Maybe you would like to read a book or go to the kitchen and make a snack.