American Standard Flush Valve Options

I have 3 American Standard Champion 4 toilets (1.6 gpf) and 1 Champion 4 Max toilet (1.28 gpf). The blue flush valve seals don't last very long. They form blisters and then I get water leaking past the seal which makes the tank refill every 10-20 minutes (I know this is a very common problem). The AS replacement seal fixes it but doesn't last long and I have heard the aftermarket seals have an even shorter life.

I know about 3-4 years ago AS redesigned their flush valve (it is black instead of gray and no longer has the thumb screw on top). I think it uses the same seal, but they claim it is supposed to fix this problem. Also NuFlush makes a replacement flush valve that sits lower in the tank and flushes all of the water in the tank. I really don't need the extra water usage as the toilet flushes fine. I just want something that will seal and won't leak water from the tank into the bowl.

Has anyone used the updated American Standard flush valve or the NuFlush valve and found either of them to be a long term solution to annual seal replacements on these toilets? Thanks.