Exy is pretty much the best type to use, there's not really any contest. You have a wide, powerful shot, and a faster, wider, more powerful laser, and fast movement speed in each. Obviously you'll actually have to learn the game rather than being able to bombspam through everything, but she has no bombs because she doesn't need them at all - weaknesses are just things that happen to other shot types. :V
She's also the best for chaining by a huge distance, if you're into that kind of thing.