At the end of the day, you don't want to fuss with your tuner and you just want tit to work. The TU-02 clips on the headstock of your instrument, you turn it on and you're done. If you use it on one type of instrument and use standard tuning, just set it to that instrument's mode and leave it there. I use it on my guitars, bass and ukulele so I just keep it in chromatic mode.
I turn it off as soon as I'm done tuning and the battery is still going strong after 10 months.
The only downside is that you can accidentally press other buttons on the tuner (ie change the instrument or the calibration) if you're not careful, but if you keep that in mind, you get used to using it.