the E go is a great electronic cigarette. Its battery is big. The 510's were too much hassle dealing with the tiny cart and filler material.An Ego with a 1000mah battery and full on tank system is kind of large to fit in my pocket.
I think that the Ego is much better rhan Joye 510. The former indeed has a bigger and more durable battery and it also gives the e-juice more strength. The latter is a weaker model and I think that it is appropriate mostly to beginners or women.