If knowing your current, average, and max watts is important to you, then get it. There is a chart that you can use if you simply want to target a specific wattage level for the different parts of a workout or just steady state riding.

I have the earlier version computer and would not but would not purchase it again. For my purposes if it also had cadence and heart rate it would be much more useful. I used another computer with cadence and heart rate to supplement and could view all the data at once and it was very helpful. If you already have a heart rate monitor it might be worth getting the computer since it is now also useful for outside use.