Choice of processor

[Peter Flynn]

I am aware of the following processors (and their LaTeX companions):

tex
pdftex
xetex
luatex

I have been steering new users towards xetex/xelatex because of Unicode 
support and TTF/OTF fonts (and newcomers are not looking for Lua scripts).

Is this still reasonable, or should I be using luatex/lualatex? There 
are some concerns reported on the Discord TeX server that lualatex is slow.

Peter

[ConTeXt is not within my ambit]