Weather data is only useful for calculating the correction needed for your first shot. After that you can use your missed shot information to correct and walk yourself in. So if your looking to increase first shot accuracy for hunting or other reasons, by all means this is a great tool to have. But if your like me and mostly shoot paper, the 4500NV gives more information than is required. Sadly, I think weather data is over kill in most situation that I face. Target shooting allows multiple sighters to get on target, so there is no need at all for weather data. I find myself using this device more for tracking altitude during a run, than I use it on the range.
The Kestrel 4500NV is a great device, but all I really needed was the basic wind reading model. I suggest you figure out what stats you NEED for your shooting situation before you drop top dollar on a unit like this.
Pros:
Measures more stats than you know what to do with
Large memory to track all stats for extended periods
Easy to use interface
Batteries last a long time
Can be calibrated
Cons:
Compass is easily thrown off, and annoying to re-calibrate
Downloading Stored data through fancy IR adapter only
Battery positioning strip could be better