Mine is currently in it's first batch - a Session IPA that has pretty much finished up bang on 4.2% (SG 1.042, FG 1.010).
First off let me say..... I LOVE THIS TOOL. My previous method of determining gravity was a good old fashioned hydrometer, which was out by 4 - 6 points and was never consistent. Not to mention I normally took at least 3 samples (SG, 7 day, ~14 day prior to racking) which diminished my fermenter by ~600ml. I have not had to open the tap/fermenter and I have been able to track where it's at every day to ensure I'm doing things at the correct time. Thursday morning I checked, gravity was down to 1.017, so I bumped the temp up 3 degrees to finish it out/do a diacetyl rest. Normally I would have waited until Saturday to check with the hydrometer.
My only gripe is that I calibrated it in a bucket of 20 degree water prior to first use, but the calibration disappeared once I moved away from the tilt and it disconnected. I do not get internet where I ferment (in a basement garage), so I haven't worked out how I'm going to get it to log data to a sheet yet, but regardless, it's still so much better than what I had. While calibrating I found that it was out by 0.002, so I have just been compensating for this when I take readings. Once I figure out how to log sheets and keep it calibrated for an entire ferment, it will near be my favourite brewing tool (except for my grainfather obviously).
Expensive? Yes. Worth it? for me..... definitely.
