I watched a short where someone took one of the Jet derivatives, launched a mini nuke, ran around the tower he launched it at, killed quite a few raiders with the Deliverance pistol, jump off the tower having the Jet wear off as he was falling just in time for the mini nuke to wipe out the raiders he missed. That is one hell of a chems build!
Honestly, the slow movement effect is just so fun to do and pull off. It hand in heart just feels so epic when you manage to do it. Chems I think are a little underrated (understandable).
Sadly not, you cannot craft it. It's a rare find in the commonwealth. Your most common source would be from vendors that tend to sell Chems but even then it's hard to find.