Lansdale is a brilliant writer. Vivid images, trenchant metaphors, visceral writing, penetrating characters, outrageous circumstances, sardonic humor. So why the disclaimer?
Lansdale also has a penchant for graphic violence, moderately explicit sex, and, the deal killer for me, a tendency to focus on the worst aspects of human nature, to roll around in the depravity of man like a hound dog in a fresh cow pie.
There are exceptions, like A Fine Dark Line, which is a riveting coming-of-age story. But as far as I know to this point, they are rare exceptions.
So far the Hap and Leonard series seems to avoid the more egregious examples of depravity, at least as compared to some of his other work, but it's still pretty raw. Brilliant, but raw.
Two guys, clever, but crude. Abrasively, flagrantly, wantonly, almost visciously crude. What redeems it from being viscious is the inherently good hearts buried in the muck of the main characters.
But the antogonists are viscious. Horribly so in most cases. Ruthless, brutal, without consience or remorse. Often juvenile in their meaness and cruelty. And the power of Lansdale's writing makes it relentless and savage.
Hence the disclaimer. I know some of my readers will be willing to sample him for his genius, regardless. Others will not. It's your nickel.