Summary: This is a very good rangefinder as stated by other reviews. I'd like to point out one thing though: It provides a slope adjusted distance but gives neither the angle nor horizontal distance, so one has no idea how the distance is adjusted. I followed its suggestion on a steep slope (30 yds down) and choose a club that is way too short -- but I have no idea whether it's reasons like wind or my swing, or the suggested distance is simply off.
Summary: There is a slight learning curve to this laser; the clubs need to be calibrated to the slope distance reading. The only discrepancy with this laser is that the readings seem a few yards shorter than one of my friends who has a Bushnell laser. I'm not sure if this unit is more accurate or if the Bushnell unit is more accurate; either way it doesn't matter once you get your club calibrated to the readings in this laser.
Summary: If you're not using it for tournaments, there's nothing more you could ask for in a rangefinder. It's fast, easy, and accurate. The slope feature isn't a problem with the product-- it does exactly what it says it will do. Lack of reading comprehension is no reason to ding the product.
Summary: I checked with Callaway about the legality of IQ Rangefinder. Their response was: "The IQ model of rangefinder is not legal for tournaments because the slope feature cannot be turned off. The LR550Y and Diablo Octane Rangefinders come without the slope feature so those models can be used in tournament play." So I returned the IQ and got a Diablo Octane Rangefinder. Incidentally, as far as I can tell the Diablo and LR550Y have the same capabilities.