I have a clone of the QJE switching power supply (30V/5A) and it is frequently subjected to very large loads under various conditions - it never gave up or showed strange behaviour. Its overall performace is quite reasonable for the price. The annoyance as mentioned before and it is the large capacitor at the output, which under smaller loads tends to reduce the voltage at a slower pace than your control.
However, the problem of the clones is that you can never precisely tell the build quality and performance from photographs - they tend to vary greatly. The Uni-T is, at least, a better known brand. If there are no reviews out there, make sure you get a reasonable warranty and/or good return conditions in case things don't work from the get go.