Kind of like the old H.G. Wells book "The Island of Doctor Moreau" i don't see this ending happily. As they said in "Jurassic Park", "Just because we can doesn't mean that we should."
some humans would probably be better off with some monkey genes in their brains.
How to test is next. Nice were genetically alter some years ago with human genes that made their brains start to fold, one of the key reasons humans are so intelligent within a limited space.
Lots of genetic mixing happening (with human cells it is mostly in the Petri dish in the US)