SF means slim frame, not short frame. The G19 Gen 4 has a slimmer frame than the Gen 3 if you leave the back straps off.
Why short change the G19's 15 round capacity? It's an easy gun to conceal. Just get a G26
Is it not a shortened frame as well? I already have a Glock 19 and a Glock 43 and a Glock 17. A Glock 26 is PROBABLY next on the list, but I thought having a "one of a kind" Glock would be fun as heck to have. I like the shortened grip of the 26/43, but I like the longer slide and weight of the the 19. Why not have the best of both worlds? If you came in just to voice your opinion that it's not your cup of tea, great. Go buy your cup of tea and let me have mine.
The initials 'SF' in reference to Glock pistols does stand for 'Short Frame'...it's 'shorter' from front grip to rear back-strap...not in width (side-to-side) as the magazine width has not changed. The only 'slim' Glock is the Glock 36 .45 acp...and the single-stack magazines are unique to that pistol only.