I replaced every toilet that came with my house and did not work, which is all of them. I have expensive toilets that work well with the limited water standard. Could probably make them work as well or better for cheaper if they were allowed to use more water. The whole thing is another gubmint stupid AF thing, much like the low flow shower heads, the light bulb thing, dishwashers and anything else FedGov touches and turns to crap. It is not like we have a shortage of water that I am aware of. My point being that I should not have had to replace every toilet in my house just to get them to flush reliably but I did.
I own a lot of properties, so I'm always on the lookout for a good toilet. I've had expensive ones turn out bad and cheap ones work like champions. There's no predicting them, you just have to take pot luck.