Doesn't worth the money.
In most cases 600d/650d/700d will perform the same, exactly the same sensor... only differs in lower noise and faster focus.
Well, if you shoot with ISO3200+ or like sport-photo... go for 7d, if not... don't waste money in it.
In my honest opinion, save your money and aim for a Full Frame camera like 6D, 5D... that is a improvement, not 7d.