It doesn't matter if it "doesn't really exist" if Vick come out of TC looking far superior he is going to start. It's not rocket science.
No, Geno will need to be completely incompetent in camp and games for Vick to start and that is very unlikely to happen. Plus it's not a competition anyway, Geno's getting 75% of the first team snaps. Competition is over in already in all but name.
Everybody is so subjective in their comments here they may actually agree while arguing with each other. PUT IT IN NUMBERS! If Smith gets an 85 and Vick gets a 90, Smith starts the season. In fact, a ten point spread will get Geno the job unless they both fall so low the ten points is something like 75/65. At that point different actors may be considered for the part.
I don't really have a clue whether or not Geno will turn it on and take the job or fade at this point. It's all on him and history tells us that some guys take a bad rookie season and use it as a springboard to a great career and others just can't get over the hump. We'll have a much better view of where Geno belongs by the end of camp. If he's looking good at that point we'll know fairly soon after that if he's made the jump he needs too.