For the most part it\'s the same (speed wise), BUT, in the later levels you are constantly dodging cliffs and all other manner of obstacles, so the speed becomes a non-issue. Many times you will find yourself throttling BACK because the turns and manuvering is tight, while the cliff wall comes perilously close to making the ****pit your casket:)
edit: HAHAHAHA they censored C.O.C.K.pit...hehehehe