Like many, MEdia Net didn't work the first few days, but I simply used Browser and it worked fine.
Now they both work, but I'm unclear as to the advantage is to using one or the other. Which is better?

The Media Net browser is a wap browser. The BB Browser is a more robust HTML browser.

Neither is "better" -- they're intended for different purposes as Pizzle said.

'Better' is a perspective only you can define, depending on your use and expectations.