Took my HF to the Snap on truck and tested against my snap on, both were on the money with that test.

Reading the title again I think the bottom line is that a good torque wrench is good, whether it's occasional or not.

In limited circumstances torque matters (con rod caps, head bolts, etc). But in most cases 'close and equal' is good enough.

If you really need a torque wrench, you need a good calibrated wrench.

When I worked at Boeing ages ago, we were taught to leave them at 20% of max torque IIRC.