You said no wind. A ballistic calculator with accurate atmospheric conditions would do the same thing. Humidity isn't a big deal, so in your case all you benefited from was current pressure and temperature. For those who don't know, elevation doesn't matter with absolute pressure.
Nearly everybody carries a smart phone these days. Ballistic calculators (with the same Litz ratings) are 10$ These also let you add in for coriolis effect if you're going really long. I don't think the Kestrel can do this. (for most it won't matter much either)
Yes, it's convenient to have it all in one package. You don't have to constantly be adding the data, but at the same time there are issues with having no keyboard so what data you do enter is a pain. The numbers on the screen are also quite small.
As I mentioned. It's a nice tool, but those without deep pockets can get away with cheaper solutions and come to the same results. It'll only give you half the story reading wind. I know wind at shooting location is supposed to be most important, but wind down range plays a massive part. All Kestrels (and other makes) read wind speed.
Happy shooting.
