I looked at a Tribeca when I was going to replace the first Outback, and I was pretty underimpressed.
But, I also looked at a newer (2009, IIRC) Forester.
I first drove a Forester in 2001 (probably a 1998 model or so) when I was contemplating my first Subaru, and I hated it. The new Forester is NOTHING like the old one I drove.
I came seriously close to buying a Forester instead of an Outback, but I just wanted that bigger car for Mason. Surrendering the entire rear seat to him, I still have a ton of cargo space in the back.
The one thing I don't much care for about Subaru is that their warranty, while decent, isn't all that great compared to a lot of other companies now. What it covers is fine, but it's still only a 3 year, 60K miles warranty. Most other companies have gone to 5 or even 10.