It doesn't matter if it cracks or not once it's under there. Use it! I use it all the time in my home improvement business. Anyone who mentions it cracking is not a flooring "expert".
Heck, you could even use play sand as a leveler if you wanted to, though definitely not recommended.
I disagree , when you shoot it with floor staples it will crack and as the flexing of the subfloor lossens those cracked spots it will begin to crack and pop when you walk on it. the real concern should be why its so uneven .first then you have to install a product that will work with the situation. just because you want a nail down product dose not mean thats the right product for the situation. OH and I have been doing floors for 36 years doing all kinds of flooring products. I would not call myself an expert , but I have worked in many ALOT of multi million dollar homes and offices. But I will tell you IT WILL MAKE NOISES.
