I don't like the finger grips on the Glock grip, they don't fit my hand. I bought a Hogue Handall. The Handall does make the finger grips larger but it allows the shooter to move the finger grips to fit their hand, especially if the shooter has large hands.
If you don't like the finger grip spacing or the stippling on the Glock grip the Handall will make your Glock much more user friendly. The Handall is made of soft rubber, giving the shooter a much more comfortable and controllable grip.
If you read the directions for the full size handall (part # 17000) they say the grip is designed to fit Glock pistols. The grip went on a Glock 19 without trimming.