Would be great if you can get some custom map too. I recommend Balloon Race v2 (or v3 if there's one), it's a combination of capture the point and racing with a
flying boat.
The boat will bring you to the next capture spot but you have to stand near the wheel to speed up the boat (there's 5 speed), capturing the point only give your ship a temporary small speed boost and won't affect your win/lose, but sending the boat to the end is what determine the winning team.
Personally I think this map is very balanced especially when the other boat is too far away, the boat will skip the captured point and take shortcut to easily catch up to the other team.
The starting point also are filled with water so pyro can't abuse as much by jumping onto the enemy boat (you rapidly lose hp when you are on enemy boat).
PS: Also a great map to get the Escape the Heat achievement.