Soldering with wires is easier, you just touch the tip of the iron to the wire when it's on top of the point you're soldering to, and pretty much, that's it. Especially with points as large as the Wiinja and I assume this require.
Personally I would prefer the Wiinja, especially since this doesn't seem to do anything different. It's easier to unsolder and get rid of if need be -- when you're soldering a chip directly to the board like this, it's much harder to remove.