Would anyone recommend being a 91F in the army small arms/ artillery repairer?

You will have much, MUCH, better promotion opportunities and availability of assignments as a 92F. In 91F there is a bottleneck at E6, assuming you are even able to make it to SSG. If you do your choice of posts is pretty limited outside of FORSCOM divisions. Many of the smaller posts may only have one 91F3 a lot on the entire post.
Not a good job if you want to make the Army a career.

It depends on if you want to make the Army a career. I spent my whole 20 plus years in the Armament. Yes rank was hard to reach, but on the other hand I to pull trigger or lanyard on everything in the Army that goes BANG.
After I retired I still work in the Small Repair world. I work as a DOD contractor . I do everything like before but I am just a civilian. I get paid very well and I love it. I have no regrets of picking Small Arms

I'm in an air defense unit, and this MOS here sucks, they basically have me with the mechanics. The SPC that just turned SGT didn't even do his job for 2 years, he was a desk jockey.
I'm new to the army and this is my first duty station and so far, I'm not enjoying it. Only time I got to do my job was for annuals and it's boring. Definitely reclassing.