Warmoth's necks are very good as delivered; no question about it. They're brand new and made to high standards, after all.
But, the frets are still raw. They're not levelled, although it's not like any of them are sitting so proud as to be a serious problem unless you're setting up to be a thrasher. They don't need to be crowned, as they were never levelled so the original crown from the draw dies is still present on the wire. They ends are not dressed at all; they're simply bevelled at about 35°. Finally, they're not polished.
The nuts are cut very well, but the slots will still be a bit shallow because they don't know what strings you're going to put on there, or what you'd consider a comfortable height for them. So, they cut for .10s and leave room for adjustment.
Raw necks are sanded to 220 grit, which insures the thing is properly shaped and is quite comfortable.
They're shipped with the truss rod loose so they're unstressed for the trip though whatever conditions they may be exposed to.
That all adds up to a neck you could install and play right out of the box, given some truss rod adjustment.
Although it might sound like I've listed a number of "cons" to buying a new neck, that's not it at all. They're supplying a new neck into a blind application by an unknown user. They don't know what you're going to do with it or what your preferences are, and even if they thought they did and tried to satisfy them some would take them to task over their efforts. Costs would climb substantially, and warranty work would require an addition on their building to handle the volume. What you're getting is actually how you want it - ready to be set up to suit you. It's entirely possible "as is" will suit you just fine, and I'm sure it does for the vast majority.
But, if you can afford it, a good setup is a wonderful thing. It's a series of minor details that are tedious and time-consuming to complete and isn't apparent to a cursory or unsophisticated review, but your hands know it when it's done. When you're spending $1,200+ on a guitar, what's another 10% or so to make it perfect?
One of the reasons retail shops are allowed to make as much markup on their instruments as they do is they're supposed to set them up for their customers before delivery. Most of them don't do it, do a half-assed job if they can get away with it or will charge if they can. As I said, it's time-consuming and costly. Avoidance is the name of the game. It's part of the reason many OEM guitars get a bad rap - they come from the factory raw, and leave the dealer the same way. If you find one that's done well, such as a Suhr or PRS, then you pay for the factory's setup and that's why they cost thousands of dollars.