I'm ready to share my FSH tale with this thread that I've read for 2 years prior to my trip.
A disclaimer, I will not give anyone any email contacts or names at FSH. I am not a VIP, just an H fan who has a great relationship with my local H in the US.
I have planned my trip for quite a while, my local store coordinated a Hermes Museum tour for me and I was able to exchange some emails about it. I also was connected with a SA to help me with some jewelry I wanted to try. I started the communication with the store about 8 weeks before my trip. I needed a specific size in a bracelet and knew I would be buying one of them. I never discussed bags, leather goods or a leather appointment in any emails.
I was able to make an appointment to try jewelry around my museum visit and had a wonderful time with the SA I had been emailing with. I shopped the whole store but only chose to buy the white gold CDC bracelet and a mineral pendant on my visit, I wanted Fall shoes but they were already in full Spring display. The SA asked me if I wanted any bags and we had a good discussion, looked at some of the new offerings and I was presented with a list of available options, about 12 different bags-not all Bs and Ks but in the range of colors I had requested. Nothing was exactly right and I didn't ask for anything to be shown to me, I prefer to let bags stay shrink-wrapped if I'm not quite sure since I think it's thrilling for a bag to be unwrapped for me. The SA understood and seemed to prefer that I was going to wait for what I wanted. I was 100% happy to buy just the two pieces I had selected. I had a wonderful time in the store and a bag would have just been icing on the cake.
The SA suggested I come back the next day as it was later in the day and I had early plans in the neighborhood the next day. There was no promise, or guarantee that what I wanted would show up but why not try? I came back earlier the next day, sought out my SA and we discussed any other things I wanted in a bag. I added black to my list after passing on two black bag options because they were not my preferred leather the previous day. This time, the SA came back with a box-not a list of options. We had spent quite a bit of time together the previous day and I felt the SA had learned my style quite well. The SA was confident I would love this option and I did. I happily took the bag, profusely thanked my SA and happily enjoyed the rest of my time in Paris.
I'll try to head off some of the questions that usually come up:
I didn't need to line up or make an appointment to get a bag but my main point of my visit was jewelry, not bags.
I watched the line before store opening one day waiting on a friend, both side and front door lines were equally long but front seemed to let fewer people in for security reasons
Do I think I could have gotten a bag without buying jewelry? Yes, because I made a connection with some of the staff by being genuine and polite-if they had a bag I wanted
Do I think they have bags and they just say no? Not really, there are probably always bags but in my case, I was given a lot of choices but none were quite right the first day. I wonder if there's a fine line between too specific and too broad so they just say NO.
Observations:
Don't try to be "that" guy or girl and ask flat out "how do I get my hands on a Birkin?" I watched this happen repeatedly and it was just plain awkward to watch. It puts the SA in an impossible situation and it's just not the right approach. It's like coming on too strong on a date in my opinion.
Don't cut the line, first of all the head security guy at the front door of H is pretty good looking but you don't want to make him mad. I actually saw some people get pulled to the back of the line trying it. I guess they do what they can if they catch it. He's really handsome BTW
Don't walk up to anyone trying on a bag, so so rude and scary for the customer!
A little French goes a LONG way, my French is super rusty but everyone appreciated that I tried and I probably sounded like a 2 year old or Yoda so hopefully I made them smile. It's only polite to take a crack at Hello, Thank You etc.
Thanks for letting me share my tale, I think FSH remains an entirely unique H experience for everyone. Some get lucky with no prior purchases, lots and lots of people get turned down and some like myself get a bag as a cherry on top of a truly lovely experience!
Here's my K25 Noir Swift GHW:
View attachment 3622308
I put in 3 different types of H wallets so you have a feel of the capacity/ relative sizing. I am using iPhone 7+ so it will fit (without any more additional space due to length of my phone) into the other compartment (left empty in my pics below) in my C18. Hope this helps u (and others) decide which C size to go for... 
