Overall HP.
I don't think he was generally evil or so, indeed identified problems with excessive capitalism, but his proposed "cures" were questionable all too often.
The big flaw with Marx was that he was good at identifying problems and extremely short on developing detailed 'cures' to those problems. His later acolytes stepped into the breach with... um... mixed results, but those by and large can't be laid at the feet of Marx the man.
He identified a good system (capitalism) and decided that it was a problem.
It’s worth bearing in mind that Marx didn’t consider capitalism to be a problem in and of itself. He was actually surprisingly complementary of it in certain writings - he considered it a necessary stage in the upward progress of humanity that would soon be replaced by socialism (a further advance), a stance that marks him out from some other socialist thinkers of the time (Fourier) who regarded capitalism and its accoutrements (trade, investment) as bad in and of themselves.
One could argue that the 21st century version of capitalism, at least in Western democracies, would be considered socialism in 1840s year, and capitalism accordingly did evolve as marks wanted. Perhaps Marxism - leninism was a schism that missed the point of Marx's teachings?