I bought FSD, but I can't really recommend it to anyone who is on the fence. I only bought it because I wanted the car to do everything that it was possible for it to do, but as it turns out - at least in Europe, and possibly for some time - what it can do is negligible above and beyond what the car can do as standard, and especially compared to EAP as it has been released today.
In the States they've got the cars driving around unaided (FSD beta) for long distances, Summon works from some distance away and the car moves spiritedly. I would absolutely feel happy about paying for FSD if I was living in the States, I think. There is nothing to indicate that FSD beta, let alone actual FSD will be coming to Europe in a reasonable timeframe.
In the UK pretty much the only thing FSD is meaningfully useful for - is auto lane changing and keeping AP enabled, which is now included in EAP. Summon is hopeless in the UK, you have to be in touching distance of the car for it to work at all. You can't even call it a party piece because it's almost guaranteed not to work at all when you want to demo it. When it does work, the car moves at a glacial pace and is hopelessly skittish, partly I presume because you have to be standing on top of the car for it to work.
Autopark? I've used it once and to be fair it worked perfectly, but I was pretty anxious about it kerbing the alloy. It only works with parking spaces I would actively choose to avoid myself though (i.e. boxed in on both sides). It doesn't work at all unless it has two cars to park between.
