I don't like the round tanks. I find the BiOrbs way to expensive for what you get in them... not to mention (as already said) the eye problems it causes fish. I also had a 360 tank before... I didn't keep it because the lid wasn't very secure and I had cats who loved to be around the tank. I also found I could never find my fish in the tank for two reasons: either the fish went down the center column and under the gravel or the way the tank was shaped you couldn't see the fish swimming in the back.
I agree with 1fish... buy a normal tank, and customize it to your likings and personality.