If GSP were the same size as Anderson I feel like GSP would win, but when GSP walks around at 190-195 and Anderson walks around at 220-230 and his frame in general is bigger I think Anderson would smash him. I don't think it's a foregone conclusion as I'd give GSP a chance as he's a great fighter but I'd put my money on Silva.
As for the comment with only maybe less than 5% being able to land the kick that Condit did, well I'd put Anderson in that category and he'd be able to pull out a lot more different types of strikes than Condit could ever dream to do. If at any point Anderson were to land a shot that floored GSP, the fight would be over once Anderson moved in for the kill. Plus I think Anderson's takedown defense has greatly improved after training for his fight against Sonnen.