If you work in high-tech industries such as telecoms, electronics, space, etc. you undoubtedly need proper instruments to do measurements. The video I posted earlier in this thread explains why.

But for the casual DIY'er or enthusiast who just needs a way to do go/no-go or good/bad component testing, these cheap meters are excellent for the money.

For example, if a 15uF run capacitor reads 15.23uF on one meter and 15.31uF on another, the small discrepancy doesn't matter. The capacitor is good!