I am in the market to buy a rangefinder partially because I noticed all my tournaments are allowing them and it seems like a great tool to have, Does anyone have any experience with them since this will be my first purchase of one. How is the battery life on them? Is it worth it to buy the real expensive ones? The gps handheld devices are out of the question because I'm not sure if I could use them and I'd prefer the rangefinder anyways.