From a functional standpoint, the Tribeca is a great step forward for Subaru - they're trying to reach a different market with it.
From a looks standpoint, I don't think it's absolutely ugly but like Tangie says, it's missed the mark as far as being a Subaru goes.
Now, have a look at the Tribeca, the Nissan Murano and the new Mazda SUV and notice the styling similarities in the body shape?