I'm applying for both the AROTC and Marine option NROTC scholarships ( as well as USMA and USNA). If I get the scholarships or get into the academies, I'm going to have a hard time choosing between the USMC and the Army. Any advice? What are the benefits and drawbacks of each?
I suggest setting yourself an exercise of laying out and researching officer communities/branches/MOS for Marine and Army.
Where do you see the most alignment with things you might see yourself doing? Are there things you would simply not like to do, or would loathe doing, and you want to ensure there is no chance in heck you are anywhere near a chance of doing that? For example, many Marine deployments, both ground and air, are on Navy ships, for several months. If you know that's not for you, ever, that could be a deal-breaker.
If you go to USNA, Marine service selection is not guaranteed; it's different than NROTC Marine option. If you didn't get Marine, would you be okay - or horrified - with going Navy surface warfare, aviation, subs, etc.?
Sometimes it's easier to do a comparative analysis by backing into it, for a fresh perspective. If you're a visualizer, draw a decision tree and weight the outcomes. Both Army and Marines are fine ways to go. It's all the same family, just different branches, each with its own culture, personality and quirks.