Need help choosing reclass route, 35L or 35G?

I would vote GEOINT. You will receive training and experience on GIS systems exceeding those who go and get masters degrees in it. You will have opportunities to learn how to task GEOINT assets, utilize imagery technology, and analyze imagery data generated from some pretty high speed technology. Outside the Army this is worth a lot. Just putting ARCGIS into your resume boosts its worth incredibly. CI is a really good job too, but it’s not as technologically robust or as STEM reliant as GEOINT. This is all from a worth outside the Army perspective. If you’re looking at what is probably a more fun job while in the Army? I would probably vote CI on that one.

Both are great and I work with a 35G. The junior enlisted do the fun stuff and the NCOs are for admin but if you get the right identifiers you will be making 6 figures as a 35G without trying.

As a 35L a e5 or E6 is really the low man in the totem pole and you will be the one conducting the operations. Also due to the rank requirements the culture of CI is very hand off with limited supervision. So that what attracts people like me to it. The down side between the two is 35G is a instant meal ticket when you get out but 35L you will get something but no where near what 35G will give you unless you are a networking monster.

You aren't guaranteed a spot for 35G, but you are guaranteed a seat at 35L if you request it early enough. Plus 35G is a more low density MOS, meaning slower promotions. Plus, you'll work in a secure room, so you should consider how you feel about working in a locked room with no sunlight.
As for outside the Army, I will tell you what I tell everyone who asks me that question. If you enjoy it, you'll stay in the Army and when you get out after a decade of managing people in your skill, it's less about your technical skill and more about your leadership abilities. If you dislike it, you'll get out and never want to touch it again. I've seen a lot of MI guys get out, get offered lucrative salaries and refuse because they had such a terrible experience. So, think about what you'll enjoy doing the next two decades, not what you think has better job opportunities.