One thing that is different is that you will be "lawyering" under the auspices of the Uniform Code of Military Justice, 10 U.S.C. Ch. 47. It is, as they say, a horse of an entirely different color.
That said, I can only speak as a former "collateral duty" legal officer in the Navy. That function is delegated to certain officers at smaller commands that do not have a JAG Corps officer assigned. Even though not a JAG officer myself, I did interact with them often.
In the Navy JAG Corps (which also provides attorneys to the Marine Corps and Coast Guard), most junior officers are assigned to what is called Naval Legal Service Offices (NLSOs). What do you suppose happens when you gather a gaggle of attorneys all under one roof? Politics, as usual. Please be advised that there are power plays made and political gaming scenarios aplenty in the military. The upside to serving is that at least (for the most part) you are not politicking for professional survival, as you would be as an associate in a BIGLAW firm.
Why are you worried about being "hoodwinked" in your accession to the military? Are you not a law student? Read the contract. There is quite a bit of disinformation out there regarding fraudulent enlistments. While faux pas have occurred, there are actually quite rare. You simply have to do your due diligence before approaching a recruiting officer. Read everything that the military provides in terms of literature.
I recommend you pay a courtesy visit to the military base nearest you. Chances are, they will have a JAG Corps officer assigned somewhere. Ask them about their typical "day in the life." See if you think it would be a fit for you. A good place to start would be to inquire at the Public Affairs Office at the Base Headquarters.
A word of caution. Be advised that even though lawyers are "administrative" in nature, they are considered to be combatants, and are worldwide assignable. Yes, you could find yourself wearing cammies and carrying a sidearm in Afghanistan.
I hope this has helped. While I know little about the Army and even less about the Air Force, I suspect that service with those elements is somewhat similar. At the very least, you are still dealing with military courts/tribunals and the Uniform Code of Military Justice.
CWO4, USN (ret.)