This is true, Tasha loves people to death (she whines and cries to meet people), but one day she thought somebody broke in... since then I know if anyone really was in the house they would have been severly bit. No one did of course, it was just a huge branch that fell down near the house during a wind storm.
If I hadn't had her since she was 6 weeks I would have thought she was a perfectly trained protection dog. As soon as I let her out of her crate she did a full search of the area like police dogs do, and did not settle until she was satisfied we were all safe and no one was there who shouldn't be. Outside of that she's a super gentle giant and loves swinging on the swing with the elderly man we live with (he's 97).
So yeah, I agree with Mikey, I'd keep her as a companion and if the need to defend/protect were ever to arise she'd most likely be by your side.