I bought the Leupold GX4i and I don't believe the benefit is worth the cost. The slope feature is OK, but not usable in competitive rounds. The club selection that takes into account slope, altitude, temperature is pretty lame since it only recommends clubs from P-wedge to 2 iron. On top of that, it doesn't sense barometric pressure (altitude) or temperature, you have to input those figures into the unit for the day and the location at which you are playing.
Accuracy is very good, and it is a big help at the driving range, I think I'd have been just as happy with one of the units that sells for around $300 bucks and saved the $200 spent on useless bells and whistles for something else.