It is full-featured, and the on-screen interface is fine, but...
The manual needs a complete rewrite by a native English speaker who walks through and understands every function and error condition. Seriously. We aren't just talking about grammar, but actual explanation of behavior and the steps to perform a function are indecipherable in several sections.
More than one section shows a sample result "screenshot" which is clearly not representative of the situation at hand as described in the text (identifying the wrong end, e.g.)
The "3. Locate the short or breakage point (e.g. metal line)" section is particularly obscure. The photo even shows the clips seemingly plugged into the wrong port, by my reading of the rest of the instructions. Maybe it doesn't matter for that case, but it's not obvious.
There are three RJ45 ports on it, and the manual does not always make it clear which one is to be used, particularly for the break tracing.
I can't tell if it's possible to find a breakage in an RJ45 cable directly, or if you have to cut the end off to access individual pairs with clips.
Ideally, you should be able to do it by plugging in the RJ45 and have the device isolate the necessary conductors at it needs, but I haven't run a test of that. If it can't run without using the clips, then Monoprice should sell the BlackBox Breakout adapter separately to use with this. The clips would seemingly be used on a punchdown block, but a trimmed conductor will not always be reachable even at the punchdown.
The probe should also have a separate protected/recessed power switch, as when it is in its case, I noticed the light turning on when in my networking tool bag. Only way to prevent it is to remove the battery, even in between regular uses.
I got this unit when it was on sale for $40 and it's worth every penny. The menu is a bit clunky to learn, and the wire length doesn't work so great. But the wire map and tracer works really good. I got this just for home use but I've started using it at work because it's better than our other testers.
Another comment I want to add but is of no fault of the device. The box it arrived in was battered to all hell by USPS, luckily everything survived.
All the features work well but this week end it really saved the day. I had an unmarked cable going from the roof to the server room I was trying to locate. I normally use a Fox & Hound tone generator and amplifier but the problem with that is it picks up noise and interference in nearby cables and completely drowned out any signal. And the tone loses volume down the cable.
Although I HAD complete faith in my Fox & Hound I thought I'd try this new tester. It was amazing. I found the cable in 5 minutes. There was no noise or interference. And even at the very end of the cable, plugged into a network switch, the signal was loud and clear. What we could not do in half a day of testing we were able to do immediately with this tester.