Just got back from a day at Carowinds... the fact that I'm back this early (with a 3 hour drive each way) should indicate how I felt about the day.
It was pretty crowded- I wasn't expecting Easter weekend to have lots of people going to parks, but they were out in droves. I absolutely abhor the implementation of Fastlane. On every ride, there is a separate entrance that leads to the load platform. The Fastlane riders then take their choice of seat before the air gates open. There is no limit- waiting for Vortex front row we had our seats taken twice in a row, and the op said that as long as they keep coming they have their choice (and so, the line for the front may never actually move). Other rides at least seemed to be running Fastlane on just one train, but still with the operational hindrance of a train load all people all entering from the very front of the station, so the air gates might not be opening until trains are already stacked.
I must give credit to Afterburn's crew who still managed to move their line pretty well. On the other hand, Intimidator's crew, one of the 2 rides where FL do use the gates, was just horrible with stacking. They also could not seem to get people in the station quickly enough, and with the loss of the single rider line trains could have 4-5 empty seats (some empty rows, despite the 90 minute line).
I realize it was a crowded day, but it still sucked to have operations so shoddy. I felt like too many people had Fastlane, and that they either need to limit it better or raise the price. Some users were also pretty jerkish about it, and seemed to take pleasure rubbing it in to guests in line that they just cut it. That's not the park's fault, but it certainly doesn't make my day any better....