There are obviously a lot of grave negatives that one could say about him but, ultimately, he left his society in a better, fairer condition than he found it.
Whether you think of him as solely a terrorist or a freedom fighter, a statesman or a charlatan, is ultimately up to yourself. For me though, anybody who summarily dismisses or emphatically praises his contributions is only displaying their own prejudices and dire lack of understanding of what used to be termed "the Irish Question", rather than evaluating a complex and, dare I say it, remarkable life.
Perhaps, rather than simply indulging in insults or hagiography, it would be wiser to just be thankful that the next generation will grow up wondering what the fuck we were all so bitter about?