Lugia is much better than Rayquaza. It can wall and sponge very well with Reflect, Calm Mind, and Recover. It can also do other cool stuff with Whirlwind, Hydro Pump, and Thunder. Some people even make it a Choice Bander with Aeroblast, Earthquake, Shadow Ball, and Ancientpower. In a fight, Lugia would win easily with Ice Beam.
Rayquaza is also good, though. It's a great CBer with Extremespeed, and it also gets Dragon Dance. Outrage sucks, though.