I am considering either 13F or 13B. Which is a better MOS?

This totally depends on what your personal interests are. Do you want to do the targeting for the big guns or shoot the big guns?

13B is in no way a better choice from ANY other MOS. Theres nothing to get out of being a 13B, whether it be personal interests or professional career progress.
And in case that doesnt convince you, I can personally tell you I've been to 2 duty stations, and almost EVERY person is either just getting out or perusing a new job. It's just a miserable existence being a 13B.

13f by far!! Best mos you have way more option for schools and units to attach to

Strong back 13B , Strong mind 13F

Fox’s get treated like the resident badass when you deploy with infantry. If you want to walk around in combat tops and ball caps with your hands in your pockets this is the way.

13B.....the Jack of all Trades

Asking which is better is a set up for all sorts of stuff. If you want to be attached to a myriad of units and work with the ground operators the 13F is the way to go. 13Bs can be utilized for a lot if things as well since the combat environment is ever changing. But they primarily shoot the big guns that the 13F needs to destroy, atrit, fix, delay and all sorts of other nasty thing. BOTTOM LINE ITS A TEAM. So whatever you pick... be the best at it.

I would say choose what you think is better. I'm a bravo and love being on the gun line. I left an engineer unit to go back to being a Smoke. FO's can be assigned to more units, same as a FA Warrant. Now if you are good at math, that might be a great route for you. Especially on the civil side. Hell he both Moss's. Most soldiers these days have multiple MOS's. I'm a 13B, 12N, 31B, 79T.

13 B all day !! There is no better feeling than saying fire and hear that loud ass howitzer going boom.
If youn want to do cq all the tike or be stuck doing dumbshit details go 13 f ,

13F