So far, so good. As you will read in other reviews, I recommend watching a YouTube video regarding installation.

That being said I am only committing to 4 stars as I just received the unit this afternoon and it hasn't had 24 hours of operation yet. What I did like was the completeness of the kit *mine included the J elbow/pipe some said they did not receive) and of course the free Prime Same Day shipping which gave me back 45 minutes on a Sunday afternoon rather than drive to Home Depot.

The instructions are clear (but very small print) and again, viewing an installation video beforehand made it that much easier to install. My only less than optimal result was that mine came with a push button 2 step flusher instead of the lever. While I was happy about it at first, the height of the mechanism which clicks in on the tank-side of the button unit is too tall and hits my tank lid. Unlike the valve assembly itself, this mechanism is not height adjustable, so my lid is *slightly* off balance on the tank. My concern is any weight placed upon the lid will push down on the mechanism - which is all plastic.

Installed on old American Standard toilet. It is unclear how to adjust it, but over the entire range I could never get a compete flush. Using the lesser flush just replaced some of the water, leaving partially dirty water. Consider this a failed experiment.

Installed this last summer and have had no problems with it. I have an old water guzzling toilet and this really made it much more efficient. I hated to toss out the old toilet just because it was "high flow", so this was a great alternative. Took me about 10 flushes to get the water level adjustments set right. haven't had to mess with it since. The low flush option uses a fraction of what the original flush used, even the full flush on this conversion kit uses less than the original flush. I have noticed a big drop in my water use on my bill too, so that makes me feel better too!
I ended up getting another one of these for my other bathroom shortly after this. very pleased with the price too, its really not bad when you consider the options.

Wow. Broke exactly a few days after the window for the return policy expired. It somehow broke in the middle of the night (no one was using it. It's in a guest bathroom downstairs). The top blue cover is where the water is draining out (like a zen water fountain, it dribbles out from under the top blue hood. This is the part that holds the lever lock and the screw for minor water level adjustment). Leaks everywhere and now cannot fill. It functioned fine before (with a few random refills here and there), but this is just abysmal. If I could return it, I wouldn't leave a terrible product review and would just review the new one I received. But this is just a mess.

Although some of the reviews here indicate that installation of this device was difficult, I found it simple to do from the instructions, and that despite the fact that I am not the most mechanically inclined person. The most difficult issue I had with installation was not having the correct tool nor the strength to undo the water connection to the toilet, which was eventually resolved by much swearing at the connection, searching the house until I found my locking pliers, and hiding them so this never happens again. (Side note, have a bucket ready, folks. I don't know what I was thinking when I didn't.) I did have to guess at the meaning of one of the instructions, but matching up what I was doing to the picture for that installation step solved that problem. I like having the dual mechanism, but had hoped that I would get a handle flusher rather than the button. This package came with the button (and if you look closely at the product picture, you can see it on the right side), but I believe you can buy the handle separately. The button is the reason for my four-star review. It is fairly small, so pushing in the top button (for flushing liquids) also results in pushing in the bottom (for flushing solids) if you are not careful. Also, the liquid flush is not always strong enough to flush paper. There are additional instructions for fine-tuning the amount of water in the bowl, which I have not yet done, but which may resolve that small issue. After one month's use, it is still working correctly, and I'm still happy. I also had no problems with the sizing as this correctly fit my American Standard toilet.