I played around with the
Vaughan V4 hammer at Lowes, it had a little different shape, and a better swing than other curved claw ones around it, seemingly more powerful for its size (I didn't even know it was lower priced there that day than I've since looked up online). The only odd thing was between two of those models there: one had a deeper and longer nail starter carved into the top. So I compared them on the nail isle, tacking different nails into the display blocks, and got the one with the shorter nail starter, where more nail sizes would fit into it (they only work well with the nail head against the back of the channel, so that's why it makes a difference). I always try to compare multiple tools on the shelf, because there's often something different between them, even though they're supposed to be identical.
The
Estwing DFH24, that I got a while ago at Home Depot, is a rubber mallet with a steel head and wood handle. I tried beating on a tire with it, putting that on a wheel, and the rubber pieces worked loose in no time. Later I had a tube of urethane construction adhesive (Loctite pro line), and remembered to fix the hammer, clamping it for a couple days with that stuff all over inside. Now it seems to be much better (it only had a smaller amount of something clear and inflexible at the tips inside, whereas the other adhesive is flexible and I put it around the edges too). I don't know about the code though (speaking of discrepancies): printed on the hammer is "DFH24", and on their website it says "DHF24". Whatever.
Obviously that's not a direct comparison, but they're all somewhat different anyway, depending on the shape, type of handle, etc. The 19 oz Vaughan is really 36 oz on the scale. I have another brand of 16 oz ball peen that's actually 36 oz too, even with an inch or so shorter handle, and then a 22 oz hammer with a longer handle than both of those, which is also (guess what) 36 oz. They were more similar in feel, when I tested them separately, than those with a different weight balance (like a wood handle with the same type of head). So I think that is what makes the biggest difference, and why I don't happen to get one particular brand over another. Wait, what is my 24 oz Estwing mallet now? 36 oz! I can't even blindly seem to pick out another weight of hammer (except for sledge hammers, of course).
Yes, it must have beeeeen a direct comparison of the vibrātiunculam factor, which I have some sense of when pounding on things (coincidentally the clerks didn't interrupt me).

No, I make it a point not to swing those around anyone in the store, especially when there's a plastic label around the grip.