This transformer has worked admirably so far. I used it on a trip to India, and it worked well. It doesn't make any noise while in use, and it seems to stay reasonably cool. Not like I'm drawing all that much wattage through it, but it seems to be just fine.Just a few quibbles:1. The 110-volt North American plug offered on the front of the unit has a spot for a grounding prong, but the unit itself is not grounded. I still cannot fathom the logic of that design choice. Especially in India, where European plugs are *required* to have a grounding prong. You can't get a plug like this one into the outlet without one; the outlets have an internal safety device that only opens when a grounding prong is inserted into the outlet. Sadly, the only way I could get this to work in India was to insert a pen in the grounding prong hole to release the safety and then insert the plug into the power holes.2. The only justification I could find for not having a grounded unit is that the unit is fuse-protected. But they don't tell you what kind of fuse is required, and the fuse is located *inside* the unit, such that you would need a screwdriver to open the unit to replace the fuse. If it is going to be fuse-protected, the fuses must be user-replaceable, and need to be easily accessible without the use of tools, which I'd rather not carry around with me when I'm traveling internationally. (See EDIT below)As far as the usability goes, it works as designed: it takes 230-240V power and steps it down to 110V power, offering you a North American power outlet. It's reasonably small and lightweight in comparison to some other transformers, but that's because it handles a much lower wattage. You have to be careful about the application that this will be used for: works well for laptops, phone chargers, electric razors, etc, but don't plug anything into it that draws over 200W, like your curling iron or hairdryer, as you'll fry the transformer instantly. And the lack of a grounded power plug and the internal fuse are poor design choices which nearly limits the functionality of the unit to the point where it's almost worth it to pay a little more for a better-designed unit.For the price, it was worth it for me. Just make sure you understand the application for which it will be used before you buy it.EDIT: I found out two new things about this unit that are very interesting.1. There is NO INTERNAL FUSE, regardless of what the documentation says. Opening the unit up and poking around clearly reveals this.2. The grounding prong hole on the front of the unit is not connected to anything on the inside; the unit does not ground the item plugged into it, nor does it attempt to.So not only is the grounding plug on the front misleading, so is the documentation. As I mentioned earlier, for the price, it does what you'd expect. In other words, you get what you pay for.EDIT 2: Some very smart electrical engineers told me that this unit has a "thermal fuse" which should, in theory, trip if the unit begins to overheat. It is self-resetting, so when it cools it should reset. Doesn't change the commentary regarding the grounding prong hole and the unit not being electrically grounded.