I've gone through several mechanical luggage scales - their universal flaw was that the "hook" used to hold the luggage wasn't secure and the dial mechanism was fragile.  The Taylor #8120 addresses both of those concerns with a secure and easy to use strap and a sturdy handle.  The weights it read agreed pretty closely with what the airline's scale did.

There are two minor gripes I have about the Taylor, though.  The first is that it does not "hold" its reading.  In use, your hand likely covers the display and it may be difficult to read before it resets itself.  I have seen other luggage scales since with a "hold" feature that keeps the weight displayed for a few seconds after.

The second gripe is that the power switch is far too easy to activate.  When I had this scale in my luggage, it kept turning on with a beep and running down the battery just being up against clothes.  This switch should have been positioned elsewhere or require a firmer press to enable.  I worked around that problem by removing the battery when not in use - not an ideal solution, I admit.