WOW I'm so confused.. I thought this thread was about BB and DB difference yet when I open it I read stuff about liars and sleeping around...
IMO on the subject since I didn't read past the women lying about sleeping with men comment... Uhhhuummm
I like DB's on walking lunges just because it's hard to load a heavy bar on your back and then walk around a gym with feet of iron and plates hanging off each side of you. It's easier to maneuver with DB's around the gym. I like the stability component also. The only thing I would be cautious of (I catch myself and other people) is leaning forward on the step up in which you begin activating the back leg and taking the focus off the front leg. I think this would be a tad more difficult to do with the BB, well if you wake up with a stiff neck and sore back the next day you were probably leaning forward. the other thing is making sure your taking big enough steps that your knee doesn't go way past your toes.
I think if it is a stationary lunge then it could only help to switch things out and maybe try the BB. Or you could superset walking DB lunges, with BB weighted step ups. OR BB stationary lunges with DB weighted step ups.
Cali and her Wood....