There's something indefinably FUN about Le Tour: maybe it's the sunshine on the southerly aspect, maybe because it's generally easy, cruisy skiing. For the more seriously inclined there's also the "backside" of Le Tour. It's steep (there are plenty of short 40 degree pitches), there's some lovely views of Lake Emosson across the valley, challenging skiing through trees and it's a powder snow-trap, often having good deep powder days after Grands Montet has been tracked out. It's well worth a visit a day or two after you've done a Grand Montets powder day.
However, there's a darker side to it. It loads up heavily with snow in a southerly wind, and the rolling tree-free terrain is perfect for setting off slab avalanches. The bottoms of the slopes make dangerous terrain traps and if you do get caught there's a high chance of being taken through trees. It's not controlled, and it's not even in France any more (it's across the Swiss border). Despite its inviting looks it's rumoured to be the most dangerous place in Chamonix. I've personally seen the aftermath of a couple of slides: nearly 1m deep slabs leaving 2-3m of packed ice at the bottom of slopes and car-sized chunks of ice. Check the avalanche reports before you go. If the level for these aspects is 4 or 5 don't even think about it.
For the best route advice see the excellent little blue book: Chamonix Hors Piste. However, here's my short summary:
Access from Le Tour: keep heading up and left to get to the top of Tete de Balme. From the top of the new lift from Vallorcine simply ski down Les Esserts and take the Les Esserts chairlift up.
Come of the chairlift and ski north, ducking under the rope (which is the border). Route choice is completely free from there: staying left will keep you in the trees (there are two clearings running straight down the slope, one under the chairlift, a quieter one further to the right as you go down. Both tend to mogul up towards the bottom. Heading futher right (east) takes you more into the open over some steeper pitches. At no lower than 1800m you'll need to traverse left through the woods to hit the bottom of the chairlift again. (The reservoir below you is far too low to ski back to it!). Generally the later you leave it the thicker the woods you'll have to negotiate. If you're not sure, follow the tracks left.
For lunch I highly recommend the Swiss house on the Col de Balme. Excellent, relatively cheap steak and a big shaggy dog in front of a real fire.
Above all, have fun, and be safe. A final request: a lot of people still seem to think it's a good idea to ski down a steep pitch and wait at the bottom (in the potential run-out zone) to watch their friend ski down to them. It's not.
I'll add photos and GPS/KML next week after I get back!