i understand the 3500 will also give you the humidity which the computer programs ask for, but means nothing when shooting
We've used Kestrels during prescribed fires to measure temp, wind speed and humidity. I was on a burn once where 3 guys had Kestrels; one was new and the other 2 had recently been calibrated. All 3 gave the same temperature reading, but standing side by side, we got 3 very different humidity values. Anymore, if we need to get a read on the relative humidity, we stick with the old sling psychrometer. I'm not alone in this opinion.
Of course, if you just have one Kestrel, you'll never have any reason to doubt its values