We were there last week and stayed at BC. We went on Thursday morning (11/17) and were at the IG entrance at 8:30 - way too early! They did let us in about 8:45 and up to right before UK. We headed straight for Soarin' but missed the first left hand turn and went over the main bridge to Future World. As it turns out, there was a rope on the short-cut path so the people going that way ended up with us. We were right behind the first group from the front gate and practically walked right on.
We went back on Saturday - we decided to ride Soarin' again first thing and then go get the monorail to MK - the kids wanted to ride the monorail. Again the rope was by the UK. We were first ones in, took the shortcut (no rope anywhere), we weren't running - I was walking fast but the kids (8 and 10) were ahead of me - and we actually beat the front gate crowd. A CM told the kids they had to wait for the CMs bringing the crowd and join in. We were on the first ride. In the first row, too. We were going to be in the third row but DH mentioned that the kids would like to try the front row so they just told us to go to the next section. It was awesome.
I would not take the trouble to get to the main gate. It really isn't that far from IG. I figured by walking fast I was burning off some of the food I ate the day before!