Ah, the centerbrace dilemma. Not to hijack the thread, but I've spent most of the last two days clearing the decks for my big tank switch tomorrow. This would have been a nice thing to avoid. At least aqua trends is being nice about it, getting my new tank ready immediately and replacing the narrow centerbrace with a standard one free of charge.

But, on your topic, I've always though that a 180 is an ideal tank shape and size. If you can get one without any centerbrace, that's great. As far as the bowing on your tank, I doubt if 1/4" along a 6' span is any indication of failure. I read once that a feather placed on a steel I beam causes it to deflect a measurable amount. That might be B.S., though....