I have the Garmin Edge 705 with the altimeter, cadence and heart rate.

I have six variables displayed which includes 2 large read outs and 4 smaller readouts i.e. font size. Cadence is at the top with heart rate right below. The the other four are elapsed time, speed, average speed and distance traveled. I only glance at cadence and heart rate.

The 705 includes the new ANT+ wireless protocol. When I get a power meter, I will add power.