I have been meaning to get to this for some time, so will add a few thoughts, bit by bit.
I joined in 89, there was less info around back in those days so you went through the gates not to sure what to expect.
Everyone had read Simon Murray's book and expected the worst.
I joined in Lille at the citadel. It is/was a French army base with an old house staffed by 2 Caporals and an Sgt. basically they do a rough selection, toss out the complete wasters and regroup the rest to send "south" once a week . I arrived just as a group was sent, so had to spend a week there. So the week spent cleaning what was already clean, smoking and playing cards. A few arguments which when they got to loud would bring a caporal running up the stairs, but not more than a few shoves and kicking over of furniture.
Next stop was Fort de Nogent in paris where a larger group was formed to be taken to aubagne. This was about 30 guys, escorted by 2 Caporals and an Adjudant. we were all ligned up in a corridor, the Adjudant hit a guy in the stomach and he folded onto the ground, we were told "no more stupid grins"... that set the tone for the trip down to Aubagne for selection...
all in all much less than i expected.