I loved this white ink pad. I think it works great. It is white ink afterall and no white ink is going to be totally opaque on dark colored paper. It worked as well as I thought it would.
The Stazon opaque ink is the only white ink I've found that actually works. Although I wish it was even more vibrant, it shows up best on really dark paper and can even be more enhanced with embossing powder over top. It's a very moist ink and a great value that the refill comes with it. You need a lot of ink to coat the stamp because of the opaqueness so its very convenient to have the refill ready to go. Make sure you read the instructions to moisten the pad correctly. Try it and you'll enjoy using white ink for a change!
I don't know if it was just mine, or if they're all this way, but it didn't come pre-inked. I've used it twice & had to use the refresher ink both times. For the price, it just doesn't seem worth it to me. Also, I still haven't found a great way to clean my stamps after using this.