Preface #1 to comments: I'm a tool junkie and a handcut dovetails aficianado
I do have the "less expensive" barell handled dovetail saw, two in fact, a LN DT saw, a PAX DT saw, a relatively inexpensive dozuki and a moderately priced japanese DT saw from either LV or Garrett Wade. Haven't tried an Adria/Ardia dovetail saw but I'm betting it'd cut somewhere between the LN and the PAX.
Preface #2 to comments: I like japanese pull saws. The kerf's narrower so they cut easier with less effort - per stroke. They leave a nice cut surface and there are so many ways to grip and cut with them - oriented up and down for ripping, horizontal for cross cutting shoulders on either the left or right sides. You can orient the stock horizonatally and sit or kneel while you saw vertically - with your face close to the blade if you need to really see the cut as it's being made. Maybe it's because I used a jewelers saw before coming to wood saws that I prefer the pull saw and am more comfortable sawing with the blade cutting up and down rather than foreward/backward. With a jeweler's saw blade, some with teeth so fine you can't see them but must rely on feel to get them in the saw frame right, one learns to let the teeth do the cutting at their own pace and with very little foreward pressure. Same thing works for pull saws but not for push saws.
Preface #3 to comments: If you've seen Frank Klausz's video on making mortise and tenon joints, you've seen his suggested sawing exercises - draw a bunch of parallel lines on the face of a board, carry the lines over the end grain then a) cut leaving the line, b) cut splitting the line, c) cut taking the line and then freehand/eyeball lines between what's left. With eight or ten lines per practice piece you can try a lot of cuts on one piece of scrap. By your third practice piece you have the feel for how the saw works and what you must do to make it work best. I did three practice pieces with each saw I've got so I'm somewhat familiar with these tools.
OK - my comments
Getting the cut started - where and how you want it is the hardest part of using any of these saws. Cutting dovetails, that involves two alignments - one "on the line" and one on the vertical axis. Chewing gum AND walking is sometimes a challenge for me so those two criteria are enough. Add a bit of difficulty getting the cut started while maintaining the saw's orientation and I'm half way to Screw Upville.
The "less expensive" barell handled saws are the worst to get started, perhaps because of the teeth set and probably because they didn't come very sharp.
The LN DT saw is next in line as far as getting the cut started. Even with a very light back draw cut and then a more forceful foreward cut it tends to chatter. That makes the start tricky. But once the cut is started, right or wrong, it cuts straight and quickly with a good cut surface.
The PAX DT saw starts a little easier than the LN though it still chatters on the light back cut. Once the cut is started it too cuts straight and quickly with a good cut finish.
The dozuki starts the cut very easily, doesn't cut as fast as the LN or the PAX and can flex and wander in the vertical axis if you're impatient. The cut surface is good though.
And then we get to the japanese DT saw. Having used the other saws and having difficulties with all of them in starting the cut, this puppy was the answer to my prayer - dovetail saw wise. Starts easily, cuts straight with no flexing, despite it's apparent delicateness, compared to the western push saws. The japanese are right when they say it's easier to pull a string than it is to push one. With a narrower kerf than the western saws, it slices with less effort and with little if any chatter.
There's another thing that you have to be able to do when cutting dovetails - and that's stopping at the bottom of the cut line - on both the face and back of the stock. There's several tricks to stopping in the right place - watching the back of the cut in a mirror, pencil line on the saw blade etc.
On all of the western saws, the spine/stiffener on the top of the blade is parallel to the teeth. If you can keep the top of the spine paralleling the top of the stock you only have to keep an eye on the bottom of the cut and the stop line. But on the dozuki and japanese dovetail saw the spine and the teeth ARE NOT parallel. The distance between the teeth and the spine decrease towards the handle so watching the top of the saw works against you and you need to see both the front and the back stop line.
Because the japanese saws cut on the pull stroke, the sawdust is pulled out towards you, slightly obscuring the stop line on your side of the piece. Not a big deal but notable.
I think you meant tenon shoulders rather than mortise shoulders. Yes, the LN works on them as well, though is limited to tenons less than about 1 1/4 inches long. The PAX will do about 2 1/4" and their tenon saw closer to 3 1/2 inches.
And I haven't - yet.