I am pretty much a beginner at this reloading lark and so my opinions are worth what you paid for them. However, I thought to post some experiences I've had over the last while in experimenting with neck sizing. This is an evolving story and will, no doubt, change with time but here goes...
When I first started reloading, say 3 years ago, I bought 100 Lapua cases and a Hornady neck sizing die which was recommended by a local firearms dealer. He was of the view that I wouldn't need to full length size for a while and so to start with the neck sizing.
Unfortunately my once fired brass, when neck sized, would often not chamber in my Blaser R93. After some research I found that many people were saying that you need to full length size for the R93 and so I decided to go down that road. I bought a Redding die set and followed the instructions.
Some time back I posted that even factory ammo fired in my rifle was flattening primers and with the guidance of lots of good people I reached the conclusion that, perhaps, the chamber of my rifle was a little long causing even moderate loads to back the primer out a little and then squash it. So, I backed the full length die off a little to allow my cases to grow a little with a view to solving this problem and it did help a lot.
I'd seen many people on this forum, and others, sing the praises of the Lee collet neck sizing die. My experiments seemed to show that the reason my neck sized cases were not chambering was because the body/shoulder junction was catching in the chamber and I concluded that the neck sizing die I had was pushing this area of the case outwards when resizing the neck. So, the Lee die seemed like an ideal solution to this problem and in view of it being relatively inexpensive I thought it worth a try.
The operation of the Lee die feels a bit odd, in fact it feels like nothing happens at all, but I started sizing my necks using it and found that it was a success. The ammo was accurate by my measure and there was no problem with the primers even as I increased the load to book max. I also found that the cases chambered in my R93 with no problems at all. The only slight problem I have with the Lee die is that sometimes it sort of "sticks" and the collet doesn't come back out of the little tapered ram thing that pushes on it. Maybe I'm putting too much pressure on the handle of my press and causing this?
I now have 5 firings, some with book max loads, out of some of my brass since it was last full length sized and so far neck sizing has been enough to do the job. I also find neck sizing simple and fast as there is no need to mess about with lube and cleaning it off the cases and so on.
So, if you don't neck size then it may be worth a try if only for the time you can save not messing about with case lube. It has certainly been an interesting experiment for me and I've been happy with the most recent results. I imagine that it will not be long before I will need to full length size my cases again but if I can get 5 reloadings with neck sizing for every full length sizing then I think that is pretty good going.