I think that this is a good tool, but with two shortcomings. One of these can be addressed but the other cannot.
The issue that can be addressed is the physical connection between the wire and clamp. It is just folded over and crimped. (See the picture.) There is even a hole there for it to be soldered in place. I went ahead and soldered mine in place and would guess that those reviewers that had issues the wire came loose and was no longer making a good connection. I checked several items at different voltages and it was spot on with this probe.
The other issue is that you have to be pretty much looking at this directly in order to read the LED. If you were working in a tight spot and needed to read the voltage this could be an issue. For my needs though this should work nicely.
Overall I think this is a nice tool but would recommend soldering the wire to the clamp to ensure a good solid connection.