They are "solid" in the context of hackintosh community (not to mention non-Intel hackintoshes are considered to be less solid and more risky even by the community). I would dare to say they are not solid in the understanding and expectations of anyone else, and I'm saying that from a perspective of hackintosh user, one of the most recommended "golden builds" with components carefully selected to be as close to real Mac as possible.
And it is still full of issues, intermittent, persistent, every OS update is a stress, every Clover/drivers update is a stress and risk and so on. Yet, for a hackintosh, it is solid.
I wouldn't recommend it to anyone and I regret spending money on it ;)