As a Christmas present to myself I got a Breedlove ABJ250/SM5 5 string ABG from eBay. I decided to pick up one of these after seeing the video on BassPlayer.tv. Everything said previously in this thread has been my experience so far, and this opinion of mine is tempered by the fact that the bass has dead strings on it at the moment (new ones are on the way). Maybe newer strings will help, but I'm still very impressed with this bass.
My thinking is that in a purely acoustic setting it will hold its own if the other instruments don't get "stupid" loud.

"Regular" loud, it should be fine.
Joe Hilgeman