The LD50 isn't the only thing that matters; you have to look at the negative side effects.
The hallucinations you experience from ODing on DPH are nothing like LSD; they're far more similar to sleep paralysis or a schizophrenic episode.
People who OD on DPH report sensations of insects crawling on their body and seeing shadowy figures etc.
It's not like other drugs where you know the things you are seeing aren't real. You will actually feel like there is a person standing in the shadows, looking at you. You'll also hear voices and feel extremely paranoid.
This guy took a 1000mg dose recreationally; you'll have to take twice what he did if you wan't to reach the LD.
I really wouldn't recommend it.