Most specifically my question ideally is for individuals that have served in both services within recent history. What are the differences in training, knowledge, P.T. requirements, unit and individual discipline between the two services?

As a mid 30's prior service active duty infantry marine that has been out for a good while and is pretty much accustomed to civilian living what should I expect should I sign a contract with a national guard infantry unit going overseas?

Just trying to figure out what kind of adjustment I should expect to make.

www.ar15.com/forums/topic.html?b=1&f=132&t=376376

It's sort of unit specific when it comes to morale and motivation.  The Army PFT is different than the Marines.  2 mile run instead of 3, pushups not pullups, and situps instead of crunches.
I'm not a former Marine, just former active Army, and for me the first Guard unit I was in was a shock to my system.  I went straight from Active to Guard and it seemed a whole different world to me.  Even now, some things seem a bit wrong.  Discipline is a bit laxer than I was used to, but then a lot of the people know each other in civillian life as well, at least in some units. That makes it more understandable.
During deployment things got a lot tighter though. Even though we were just glorified rent-a-cops.
One thing that annoys me was the people (usually the ones who's rank insigna are bars and leaves) tried to be so much "harder" or more hooah, or whatever than was needed.  Like they wanted to show that they were just as good as active duty or something.  Perhaps they have an inferiority complex and need to make up for it.