My PERSONAL opinion is that I'll stick with a LBS bought bike until (if?) I ever get below 200 pounds. I like to try out how they ride before I ride 'em, and I like the relationship built by dealing with a LBS instead of a online retailer. Said relationship definitely comes in handy when you are attempting to work through serious issues with your bike(s), which is something that I can't say about online retailers.
Now, some may vary. Some LBSes are WORSE than online retailers, I've seen (but don't deal with) ones that are. In that case you'd be hard pressed to make a definitive case for either, but probably better off going with something that you can fix on your own without too many issues.
I've also seem some BD bikes in person, and they are impressive. Granted these are the highest end BD bikes (their Record, Force and Dura-Ace Carbon bikes), but they really are beautiful and well put together machines.
My summary is that you need to do what's best for you. Being a beginner, I'd suggest you err on the side of caution and avoid BD.