You'll get a lot of different opinions on if you should order FSD right now.
For me, FSD is *currently* vaporware. There is nothing this provides you other than a checkbox on a configuration sheet. As such, I didn't spend the extra money on nothing because the car could be totaled in an accident tomorrow and that $3k spent would have been a total waste. The value in buying it now is to avoid the premium to purchase it after the fact, which needs to be weighed against the risk of never being able to use the software feature.
We are told to expect software version 9, which will include the "first of the FSD features", in the next month. I think an August release was specified, but I'm not expecting it for another couple months. As the specifics of these new features are announced, I'll personally do a new evaluation on if I feel the feature is worth the price of the FSD upgrade. This will likely involve travel to a Tesla store to get a little seat time in a demo vehicle with the new software. At some point, they may add enough individual features (stop light/sign recognition/handling; actual speed limit sign reading instead of the sometimes broken GPS/map derived info; navigating surface streets, handling some construction zones, handling crosswalks/pedestrians, handling ...).
Over time, the feature set will mature and at some point it will be worth the purchase price. For now, I fail to see the value in the non-existent FSD feature.