What umd said. As well as the fact that the 705 is so badass. I'll use the directions to stop from getting lost, which I do frequently. I'm also looking forward to having cadence, HR, power, speed, elevation, etc all on one chart. Looking at how all that works together I think will help make me a better racer. I'm hoping to learn things about how spinning helps me, looking at how well I climb/descend, checking HR against speed and power, etc.

But the MAIN reason for getting the 705 instead of the 305 is the ANT+ capability to add power next summer when I get a meter.