Everyone has had such wonderful input - thank you!

Well...to answer some of your comments (and hopefully this will help me make a decision - with your feedback, of course!)...

1. I definitely don't plan to *replace* the bike, but maybe buy another one to add to my collection . (I never in my life thought I'd be saying something like this.)
2. I am definitely more a "runner" type. Even on my trail run on Monday, I realized I just love running and feeling the dirt under my feet, hopping over rocks, crossing streams, etc. I can't imagine feeling that connected to the trail on a bike. Of course, that's not to say I wouldn't try it, because I'd love to! But I think the feeling will be different, and I will always consider myself a trailrunner first.
3. Racing...I think I'm OK on a road bike, but definitely not competitive enough. I will probably keep my competitive bug for running events only. But who knows, I may do my first tri (IronGirl Columbia, actually!) and decide I need a lighter, faster bike.
4. I do like the idea of having a good, reliable bike I can keep for long time. Maybe do a charity ride here and there. Possibly even a century (though it won't be fast by any means).

Do you think the Sutra will fit the bill? Eden, I had thought about the price. It's a bit much for a "casual" bike, but I also loved it. I wanted to test ride that thing all the way back to my house 30 miles away! But if I consider it my good ol' reliable, go-anywhere bike that will start my collection, maybe it's a good investment?

AAAAHHHH. The more I learn about the bikes, the more difficult this decision has become!!! Two years ago, I would've been totally happy with a $100 bike from Walmart.