I recently picked up a Brunton ADC Pro, initially for the altimeter, though on trails I've gotten a lot more use out of the thermometer (and the clock). Listed at 2.4 oz, it's fairly "heavy" but it gives time, temperature, wind speed, barometer, and altitude, and has a decent logger.
The logging feature is fairly painless to use, and holds a few thousand records - I set it up to take a full set of measurements every 10 minutes for the duration of my recent 5 day hike. You can also change the interval, so you could set it up to take a reading every hour or two if you're going on a longer trip. My issue with min/max measurements is you don't really know if the extreme min/max were sustained or just achieved for a brief period, say where it was really windy, or where you left your bag on a hot rock under the sun. Maybe it's not a big concern, but on the Brunton it's actually surprisingly easy to scroll back through the logs, so you can tell whether that 16 degree minimum was sustained for most of the night, or a relatively brief drop from 4 to 4:30 am. The logging feature isn't at all why I bought the device, but in retrospect it was actually pretty informative.
- As Jerry mentioned, the thermometer is somewhat slow to respond.
- The logger beeps every time it takes a measurement, and I couldn't figure out how to turn that off. It's faint and I got used to it, but it still takes away from the nature experience. Also when you're sleeping you'll want to stick it somewhere where you can't hear it.
- I believe the altitude is based off of the barometer. So for the altitude measurement to be useful, you probably need to be vigilant about recalibrating when you're at known altitudes. (I didn't, so it wasn't).
- It's also heavy and expensive.
As for experience with it: On this last trip I planned ahead of time for overall night-time temps from 20 to 50 degrees, but on any given night I did find myself slightly changing my sleep prep based on the actual measured temperature (and windiness). Below ~40 I'd probably sleep in my down jacket and spend a little longer looking for a site that was well shielded from wind. Below ~30 and I'd zip things tighter and wear a winter hat inside my mummy bag. And the colder it was, the more likely I'd be to opt for a fattier dinner if possible. If I was contemplating a summit near dusk that might leave me camping high and exposed, I'd be more likely to put it off until the next day if I saw that the temperature was dropping.
I don't know if I'd bring the ADC Pro on every trip with me, but for calibrating myself -- how I react to different conditions -- I'm pretty happy to have it. My guess is after a handful of more trips with the Brunton I'll probably switch to something lighter when I'll be in familiar conditions.