I'm trying to compare my Gen 4 grips with the G21 grip. So my G22 Gen 4 med backstrap is equal to Gen 2/3 standard grip G22. How about comparing the Gen 4 with large backstrap to a G21 and G21SF.
The large backstrap adds 2mm over the Gen2/3 size as measured front to back. It's going to be very close (front to back) to the G21SF. That said, the G21 will still be fatter so it's not an easy comparison really.....
