Being unable to cross the street was indeed a problem for me during last year's parade. It was until the parade was in essence over that I could get from the east side of 5th Ave to the west side and into Central Park. During last year's parade, there was heavy rain for around 20 minutes. At that point in time, I was fortunate to be on the east side of 5th Avenue, as I was able to find shelter on one of the side streets between 5th and Madison Ave.
While giving out anti-Obama material the previous 2 years, I basically didn't even notice the vast majority of the actual parade or concert. Based on what you mentioned, the concert certainly sounds like the better event to attend. I met many great people that were against Obama. Unfortunately, there were also too many leftists.