What are the biggest differences between the Guard and the Reserves?

Thank you for the insight sir!

The National Guard has the combat arms. Armor, Infantry, Special forces and artillery. National Guard may also have military police and some Logistics. Army Reserve will have psyops, civil affairs, medical service Corps and the remainder of logistics like Transportation, quartermaster and ordinance. For officers, those at Major and above don't have to work for the office of the adjutant general if they want to get a battalion command. The Army Reserve cares more about the schools than the mission. Many Army Reserve units will pay up to $500 a month for travel expenses and put you up in a hotel. I don't know of any National Guard units that do that. Army National Guard has a maximum age to be commissioned of just under 35 years old while the Army Reserve the maximum age to be an officer is 32 and a half. I joined the National Guard for 12 years and then switched to the Army Reserve. Army National Guard can be called up for State emergencies such as Riot, earthquakes, flood or fire. I am sure the Hawaii National Guard is being called up for this volcano eruption. Army Reserve soldiers generally cannot carry ammunition when being activated for civil disturbance in the cities while Army National Guard soldiers even from other states can be deputized to carry ammunition during martial law such as after Hurricane Katrina. Each branch of the army has their own pros and cons. In OCS, Army National Guard soldiers are paid at E6 rank while Army Reserve soldiers are paid at E5 rank.

I did not see the problem with promotions in the lower ranks in any of the National Guard units that I served. I served in both Infantry and Combat Engineer units and never saw a promotion problem because of lack of slots until at least E7 for enlisted and O4 for officers. I may have been lucky that I served in one state that had a Separate Infantry Brigade and then in a state that had two full Battalions of Engineers. If you are in a small MOS with few positions, yes, it can be a problem, but it would be a problem in the Reserve too unless you are willing to travel.