I have a Canon 7D. It is good. But the nikon D300s can play around with the in-the-face more. But it take time to get use to the buttons on the nikon D300s.
A camera is a very personal thing. The best way is to buy both n try. U can subsequently sell the one that you don't like. Both cameras can fetch high resale price in the 2nd hand market. Go chk it out! U won't loose much!
You have been trying .. to what result? What conclusions have you drawn already, what is open? Please share a bit more about your efforts. Not many people have both cameras and those who own either one of of them can only give you feedback about one.
A simple side by side comparison can easily be done on the usual review sites like www.dpreview.com.
"Better" depends on a baseline of needs and purposes. What are yours?