Jamarcus Russell comparisons are a stretch. I think Garrett shows that he is the same style of quarterback as JR, in that he is decently mobile, big, and strong-armed. But JR, at the same point of development, was significantly bigger and stronger-armed than Garrett. In that way, Garrett is like JR, except less so. Garrett can be a very good QB, and may very well one day be our starter, but he does not have the physical upside JR has. Which is fine, because almost no one does.
I hope Garrett has some football smarts, game management skills, field presence, ability to read defenses, etc. that Russell never had. Without his right arm JR was nothing. :laflagwav