Unless it's the husky coming with me, I definitely prefer to ride alone. There's just the feeling that if I'm riding with others, I can't stop and enjoy the scenery, take photos. I'm just killing myself and my knees to play catch up since even when I'm not dawdling, I'm quite slow.
Sometimes I think it might be nice to have company while I do it, but then I remember that I would just be spending the entire time looking at their backs in the distance and think, "Oooh, yeah. Company would be great!"