I'm also on the east coast, and use a knife to get to dry wood – since the outer bark and 1/8 to 3/16" of the actual wood is typically water logged.
I fondly remember living in the north west, where it also rained a lot – but had pine trees of various sorts that always had dry twigs attached to the trunk down near the bottom. The only time I've seen an evergreen tree on the AT within a 3-4 hour drive of my house is at the entrance to the state park – where they are planted for ornamental purposes.
The state and federal forests and AT in my area are all very mature hardwood trees, whose lower branches fell off decades ago. Now the branches start 40 ft up where the canopy is. As a result, the dead wood is always laying on top of 6" of wet leaves and in the shade…
I split 1" thick branches into quarters to get kindling, and whittle a couple into slivers to get tinder. I occaisionally have to split 3" thick branches into 1" pieces because all the hikers before me have used the smaller branches on the piece of blow-down already.
For splitting branches up to 1.5" thick – I use a standard 3.5" Swiss army knife :). I've done this for several hundred splits and have no changes to the hinge of the knife. The Swiss army blade is so thin that once you get it started by wacking it with a baton, you can just hold the handle with 2 hands and force it down through the wood like you were cutting. Most of the time, you only have to go down a few inches, and the wood splits the rest of the way by itself with a big cracking noise. You just have to avoid twisty knotty wood for this to work.
For 1.75-3" thick wood, I use a mora clipper (4" thin fixed blade, weighs 3 oz with thin sheath). This allows you to wack the tip of the blade sticking out the other side of the branch downward. The thicker wood doesn't split nearly as easily… The extra fibers seem to provide a lot more "glue" to hold the piece together.
I've tried a couple of Mora's and found that the thinner blades split wood way easier. The composite blade (hard core with stainless wrap) is too soft and bends when the blade splits the wood near a knot. The high carbon blade stays sharper longer than the stainless blade.
I'd also suggest a small pruning saw. Splitting wood is pretty easy with a knife. Cutting it into fire-sized lengths is really really hard. Notching the wood and then snapping it looks easy on the Internet – but boy is it hard to notch seasoned dry wood :(
I noticed that victorinox brought out a heavy duty series for the Army a few years ago. They were all 4" folders, and most had a saw. I've used that model once. The handle is way more comfy for splitting small sticks without a baton, way more comfy for notching branches to make a tent peg when you lose one, and feels very sturdy at the hinge. The blade is still thin, so it cuts well- but since it's thin and longer it feels like it could snap easier if twisted while batoning. The saw works well in the 4" size though :). The 3" saw is just a little too short to move back and forth without it leaving the cut.
I wouldn't recommend a neck knife for batoning or splitting wood by hand. The 2 things you need are a handle that is wide enough to push down on hard without it biting into your hand, and a blade that is long enough to stick out the car side of the branch so you have something to hit with the baton. I think a neck knife might be handy for general purpose use though :). Although I think the 1.5" victorinox Classic I use for general use is handier due to the scissors, nail file, and tweezers.