The exhause cam lift of gsr and b16 is the same at 9.7mm. The intake gsr adds .2mm lift. Put two pieces of notebook paper together if you want to get an idea how much .2 mm is. GSR cams have more duraction than b16 but lift is the goal when boosting, limiting duration and overlap to keep the boost in the cylinders where it belongs.
If anyone has a graph to show appreciable gains using gsr over b16 in boost applications, I would like to see them. Just don't think there is enough potential there to worry about it, but again, if anyone has some numbers.....