V-brakes can have plenty of power. The problem is almost certainly your Dura-Ace levers. Almost all road levers (the kind made to go on drop bars) do not pull enough cable to work well with V-brakes.
If the levers are your problem, there are a few solutions. You can switch levers, you can switch brakes, or you can add an adapter. Dia-Compe makes road levers for V-brakes which work well, but they are just levers, so if you have integrated levers (brifters, STI, whatever) that solution might not be so good. You can switch to cantilever or caliper brakes, which both work with road levers. You can also add a little doo-dad called a travel agent (forgot who makes it) that goes in the cable line down by the brakes and increases the travel so the V-brakes will work fine. That would be an especially good thing if the Dura-Ace levers are integrated and you want to keep them.