Yes you need to be there before store open to queue up. There are two lines (outside main door and side door) and they usually let main door in first. Then staff will instruct you to continue queuing inside the store for appointment booking. They will register your name and mobile number, then your phone will receive a link which you need to click in to see your appointment time. The time may change so you need to keep refreshing the link to check.
Normally appointments will be full at around 11:30am so you have to go early. They don't serve walk in customers at leather department after this system implemented.
Ridiculously stupid system if u ask me! I was there like 10:45, super crowded already n I did line up for the appointment but then at one point they were saying its full for the day, no more appointments can be made and ask ppl to come back again tmr etc. I chatted w 2 sales there n I was told that it doesn't mean u can buy a b/k/c even u are the first one on the queue. Still depends what they have at that time..so really no point of queuing there..
I went to the shop on rue de sevres, got what I want too!! Very pleasant shopping.
Depends on which bag you are trying to get. If you're looking for b/k then fsh has the highest chance. You can get other styles at George v or sevres without needing to queue