I had a 21SF for a while. Liked it a lot but ultimately ended up letting it go in favor of my XDM 45.
Same boat...But I used a raft to escape the boat we shared. ie: I went with the XD45 because I wanted something different than Glock. Feels amazing!
For the OP Glock 21 is great, and I love the huge grip..To be honest, I have massive hands. Anyways, my aunt who is 5ft short has and carries a Glock 21 with her and it's her only gun...So she knows how to use it. She's been carrying it since 1998 or so. Good choice man, take care of it.
Anyways, have you seen the TV show "Justified" ? The main character carries a Glock 21 in the show and brags it a few times. When he had to give it up after a shooting for the US Marshall Service he had to give it up. When they asked "So what are you getting next?" he said "Probably the same thing" lol
^^^^^^^^^^ last paragraph was for humor
(but is factual)