If you rate the product on amazon and send them a screenshot, they pledge to give you an additional honing disk (see their official website). Granted they don't ask for 5 stars, but people may feel awkward about putting a bad review in that scenario, so keep this in mind while reading the reviews.
Quality: the actual block and roller feel solid and good quality. The magnets are very strong and feel secure when sharpening the knife. However, I will echo a few other reviews that say that the disk don't feel very durable. I have sharpened two admittedly very dull knifes with it, and both disks feel much smoother than they originally did. I would expect the disks to last for longer than they do for the price, quite honestly.
Sharpness: The product does sharpen knives adequately. It won't be ''cutting a paper with no resistance'' kind of sharp, but I feel like it would be sharp enough for about 99% of users. For the effort required (i.e minimal), it achieves a great result.
Ease of use: very easy to use. Getting a knife from dull to sharp can take some time, but maintenance can be done in 1 minute before prepping food.
Overall, I recommend the product, I just wished the disks were a bit more durable, especially with the steep price point of replacement disks (45$ each at the time of writing this review). Almost feels like it is on purpose when 1 replacement disk is 1/3 of the price of the full product...