I own a Davinci Ascent, which has worked well for @ 4 years.
However, the unreplaceable rechargable battery will no longer hold a charge very long.
I do not reccomend any device that you can't replace the battery.
The Davinci IQ is well worth the price.
The battery is replaceable, the size, comfort of use, features and warranty are great.
If it were to not work, I would buy another.