I use Ngteco for a small office.
I have the cheapest model and it works.
Issues I have with it:
Can only access punches thru wifi on the same network using the app or USB key (cannot access on computer),
Users need to select in or out. If they choose wrong, the calculations are messed up,
Adding punches and fixing the above can only be done thru app and its not so easy to do.
Not sure if the better models also have these issues.
But, even with all this, it is accurate and biometrically secure. Mostly my workers choose in/out correctly and the timeclock is a huge time-saver.