Putting emphasis by capitalizing some letters, can be deceiving. It may look good on a billboard sign or a calling card, but not so when you see it as a URL on your browser.
So the word "chicago" is not as obvious when you see it as "ichicago.com" (could be mistaken for some spanish word at first glance), compared to "chicago360.com". Small caps.
I believe the i infront of words is more of a trend and is likely to fade out with time. I would not reg any iSomethings for end use at all and believe the time to invest in them has come and gone. Go with 360.