FastDL or Workshop for server ?

Go workshop and FastDL because FastDL is good and is bug

FastDL is the best of the two but you need extra equipment at FastDL.

FastDL should only be used for non-workshop items. Workshop DL is optimized and fast. While FastDL servers have a limited space, depending on your provider, and should only be used for items that you don't want to upload on the workshop.

Everything else should go to the fastdl in case the workshop item gets taken offline. However, don't forget that you only need to put models, materials, sounds (and anything else player-based) on the fastdl.
Lua-Files don't belong there

FastDL has a limit to the jump of ~ 4000 files, so if you want to download more than 4k it's worth looking at WorkShop.

workshop, because fastdl requires extra configuration, which is a pain.

Use FastDL for the little models & materials you have on your own server, but for known contents like cars & weapons, use WorkshopDL. Just an advice from someone who had a popular server.

If you're going to have a lot of addons might as well make it a workshop. But if you're going to have a little bit of addons where it takes at least 10 minutes max to get into the server then might aswell make a workshop.lua file and get cracking.

FastDL is faster and better, than workshop. Its better for server

WorkshopDL is definetly faster, I use it for almost everything I can.