No doubt the individual (McNabb) will be much better. Problem is, the rest is under construction. So, while you'll be surrendering what might amount to more than a #2 pick, we'll be learning a new offense and defense. That goes for McNabb, too. It won't be business as usual for him. By the time we're ready to roll, if the present regime provides what is needed, DM will be in what I would call his last good year.
That's IF all goes well. There is no quick fix. Lightening ina bottle? Maybe. Don't count on it. Sustained success will take time.