I have heard guitar reviewers speak about this type of neck before, but I never really had an explanation of what exactly it is. Is it always better to have this on a guitar and if so why don't all guitars come with it?
Rather than perfectly flat, like a ruler, guitar necks feature a fretboard that has a slight curve or arc to them, like the middle part of a baseball bat.
Most guitar necks have a radius that is consistent from top to bottom. This is easier to manufacture, and less time consuming for the luthier or production line worker to craft.
A compound radius guitar neck is one that features a rounder radius at the nut (top of the neck) and a flatter radius at the bottom end of the neck (where it joins the guitar). This innovation was developed by Warmoth almost 30 years ago.
This feature is said to provide the player with maximum hand comfort in the chording area, while allowing greater speed and cleaner string bending as the player moves up the neck.
I personally don't find it to be a big deal. I play both rhythm and lead, but am not a lightning-fast shredder (like Rob Chapman or Paul Gilbert).
Unless you are a highly-technical, extremely fast lead guitar player, I would not make acquiring a compound radius neck a high priority.