In use there isn't any. The LV saws are as good as any, when you buy a boutique saw you are mostly buying bling. Having said that I like bling and have a full set of Bad Axe, several LN and Gramercy saws. The biggest difference with a saw like a Bad Axe with a folded back is you can take it apart and repair if needed. The molded back of the LV and milled backs like on the LN you can not and that basically makes that kind of saw a throw away if repairs other than sharpening are needed.I find the dozukis are for fine small DTs but for larger ones in something like pine the western push saws work better and faster. I have the Vertias from LV but would really like to try a brass splined just to see the difference.
That is what I did, bought all the L.V. Vertias saws and really have no complaints! Do have my eye on a Gramercy from L.V. How much of a difference between 15 and 18 tpi? Also have a small problem when it comes to Chisels, hand planes and WOOD! ( Scotch is another weakness lately )BTW, even with tool porn saws in my saw till I will use the LV saws almost as often as the others. For folks starting a saw collection to use for woodworking buy a full set of the LV s first. With the LV you can do anything needed to make furniture and they will do it as well as any other saw. Then if you would like a little eye candy for your till go for what ever saw blows your skirt. One set to work with, one set to look at, it s win win.