Sorry, no experience with the marine reserve.
In the Army Nat'l Guard (you can)... sorry, had to.
But really, they figure every deployable unit will probably go overseas once every 5 years.
I believe the Army reserve is more often, as they are a federal level defense, rather than a state level.
So I would be willing to bet that if you got into the marine reserve, in the next 5 years, you would see the sandbox.
Granted, also depends on what our next Commander In Chief has in store for us as well.
Good luck with whatever choice you make!
I've never regretted joining, and I'm proud to be an American, and that I'm allowed the opportunity to serve and protect this great country.