I use and enjoy those too, Rob, but the one I use most is the little mini pry bar. I grind its end even thinner than it comes, and do the same with the upholsterer's tack pullers. The very flat ends are great for getting under the heads of tacks. The mini pry bar's two different ends (like the Vaughn) gives you two different fulcrums, which helps. I'd love to see what a ground-down Vaughn's end looks like. After using a flat tool for so long it's hard to imagine how that end gets under the head of a tack. By the way, I also use the putty knife or another thin piece of metal as a backer between the tool and planking - makes a big difference.
If anyone reading this hasn't dealt with this issue and wonders why so much attention is paid to such a seemingly simple task as pulling old tacks, just try it and you'll understand. Getting tacks out without too much damage to planking takes some skill and good tools. But with practice, the tedious chore of tack removal can become surprisingly efficient.
By the way, I'm with Mike - I try to save everything possible when doing a restoration, and parts that must come out hopefully come out as intact as possible so they can be used as needed in other restorations. These are canoes that are either nice historic examples or they are someone's family heirlooms. There is rarely any ripping out and replacement, but that approach makes sense on utilitarian canoes that just need to get back out there. Maybe I spend too much time (in some eyes), but like you, Mike, I want to see as little evidence of repair and replacement as possible. I'm working on a 1922 17' Carleton, a fairly standard CS-grade sponson canoe that iis a very well-used family heirloom. The bow sailing seat was literally in about 12 pieces with a hunk of pine plus iron nails and screws barely holding it all together. Perhaps I should have just built a new seat frame, but I thought "Why not try?" and proceeded to piece it all back into a proper, functional seat. It turned out even better than expected, it retains lots of historic character, and the owner is extremely pleased.