Took the U3 out in the field in a car for the first time...in a backup vehicle with no radios installed, so I needed every receiver I had on hand. The U3 speaker output is, well, it has a speaker that makes some sound. Audio output is extremely low, basically unusable while driving. Compared to the 500mw audio output of my APX4000, the U3 puts out maybe half the usable audio lecel, due to speaker being behind the keypad, with only a few tiny slits for passthrough. I would rate it at 300mw max, similar to the Unication G series pagers. Unlike the G series pagers, there is no audio distortion at this 300mw level, no background DSP hiss, and the DSP delay is identical to a Motorola APX, meaning no annoying echo effect when they hit on the same talkgroup.
I really wish I could find a use for this thing. No multi system scan, no priority scan, no nuisance delete, changing zones requires intense staring at the screen with menu going away upon talkgroup receive like G series, and the process being very complex and taking around 10 seconds. Add to that the extremely low treble audio, heavy weight, no real RSM or accessory options. The boot up time from powered off is also 1 minute 15 seconds...you have to remove the battery and put it back on or else the radio stays in standby and is dead on a week.
If you need an in home desk radio, with good RX sensitivity, non affiliate scan, to lock onto a single talkgroup at a time, or don't need to change zones much, this could work out for you, otherwise, buy a used APX1000/2000/4000 for under $1000.
Paul