LONG time lurker (such a seedy word), first time poster.
I tried to pick up an iPhone X on launch day only to be let down by the App on 2 devices and ended up ordering on the website but with a delivery of 4-5 weeks (28th November). I honestly think Apple will improve these dates in the coming weeks.
For all the people thinking of trying to get walk in pick ups - i have phoned 2 stores and been advised not to as its likely there wont be any as most, if not all, will be taken by reservations.
I have ordered with Three for delivery on 10th (they are still taking orders on Silver 64GB for 10th) but I had to buy out my existing contract and pay for the phone up front - came to about 750-800 so 200 cheaper but my tariff is an extra £12 a month.