I stood there in '98(?) Paulus - on the river side - there's a walkway from the Seine IIRC and I was on a corner or the road on the river side of the Place.
As Steve says - massively busy and 'crowd control' (you don't mess with the CRS
) means that spectators are well back but the riders come steaming across in a fantastic 'whoosh' of bikes.
Lovely spectacle though and afterwards the victory parades up the Champs Elysees...
Take the biggest lens and camera you can if you want to take pics!
Otherwise, save your efforts for the team areas afterwards, where you may get closer to the wheels and riders.
I'll always remember that little brat of an Italian kid with the loudest, most piercing squeal chanting "Pantani, Pantani, Pantani, Pantani..." non-stop for twenty minutes or so...he and his parents had a 'zone' to themselves eventually!
Also, don't forget to stroll into Angelinas opposite the Louvre (Rue de Rivoli) for the best hot chocolate in town (a L'Africain). Complete with all the yummy cakes and classy service.
Drool
You're going to have a great time. Mind your wallet and Mrs P's handbag in the crowds too!