I too have the Kestrel 4500 AB, Generally speaking it does the job of multiple units very well.. it saves space in a backpack by eliminating those units. I've tested mine on a number of calibers as far as 1315 yards, far as my range can reach* Just as long as your inputs are correct, the solutions will be too.. I like the feature of "two" velocities for different temperatures. In one particular rifle, that feature (in my opinion) paid for the unit in it-self..
However, there is one problem with those units. Pretty certain Doc will vouch here, he addressed it in a separate thread not long ago, it relates to the batteries and cold weather use... and I've noted the problem on mine act up someplace around 10deg F ~ At temperatures below that, the lithium batteries start acting funny and the unit doesn't work too good. We were out last week in -14 F temps, with some wind-chill on top of that, my Kestrel first was stubborn to turn on (lithium battery thing) but even once it did, the Baro-pressure wouldn't read, elevation wouldn't register, temperature wouldn't register.. and the solutions I was getting thru my (otherwise very accurate AB info) were way out to lunch* I will say though, the windmeter portion of it, did work in the cold. So long as it would turn on, that much was somehow okay.
EXTREME COLD WEATHER ASIDE THOUGH, they are awesome... and they-are very accurate. The extreme cold just isn't where they shine. Most guys don't shoot when it's that cold... I do because somedays those-days are the ones I can get away to shoot, other-days I just like to know where the limits of my gear are.. and the applied ballistics portion anyway, of the Kestrel, is crippled by the cold. Unfortunately.
If kept in an inside pocket, it can still be used under those conditions as a basic windmeter, but over and above that, be sure to-have proven drop data with-you to make your shot, IF it's very-very cold*
