The crowds before the Convention while respectable for Romney are dwarfed by what we have seen so far after the convention in Jacksonville and Cinn.
Rasmussen's report of the Rep. ID being at the high point in the past 8 years and the Democrats at the lowest in 11 years, along with the big lead we see for Romney over Obama with Independents gives me the sense of a gathering momentum. Also I believe the Romney teams decision to use the “bringing America back” theme as opposed to the slash and burn negativity of the Obama campaign is playing very very, well across the country.
You're right - it's the best ground game for this stage... many of us are impressed with the Romney/Ryan team - and pleasantly surprised by how well they're doing...