Looking at the video, that doesn't look to me like it keeps him away from the front tire. I'd worry about turning right into him. I use one of these along with a collar and leash for just in case. I like the dog back further.
At the fair, my dog went biking with it (I wasn't the one riding). The bar did prevent her from turning into the front tire because she tried to turn towards me and the J bar got in her way so I feel pretty comfortable about that.
I'm interested in getting one too but I worry my dog will turn to the right and pull me off the bike. Ouch
My plan is to tie her to whatever bike equipment I get then also another leash on her collar to where my handle is so I can still steer her when needed (or use another collar that I won't verbalize here to avoid discussions on that). She already runs nicely next to me with just the leash on my handle bar.
When she tried out the Dog Runner, it worked great on her even though she was a little disturbed that a stranger is taking her instead of me and was all over the place in both directions trying to get to me but there isn't much pulling force on the bike because the leash is short and is level to the dog (rather than above her).