I have two opinions on it.
firstly, I've never seen it where you only have to be there 45 minutes early. NEVER, and I go all of the time! I'm not saying it doesnt happen but maybe it's in slow times and I've never seen it.
I've gone many many times and only had the opportunity once and had to be there 1 1/2 hours early to get the seats.
The cons: Well remember that the lighting on Main St. does not turn off during wishes, and that may take away some of the effect for some. Many like the end of Main St. where the lights are all off.
Even at the train station, as time gets closer, people start crowding around and you dont have the nice quiet little spot you expected. You dont have your own space either. Expect people literally trying to stand beside of you, inches from you, or touching you and it to be like a can of sardines, even in your chair.
Put it this way..........I was on the front row with a seat, and in my camera view are elbows and peoples sides.
It's not a bad spot to watch, but for what you get, and how early you have to get there, basically I feel it's a wasted hour of my vacation that I could be enjoying doing something else.