I have read through this and I think I am more torn on it than to begin with. I am real conservationist. I value our palmer and its life forms. Both sides have such compelling arguments. On the R&D side of things we have a great potential to find and discover new treatments that end once thought to be incurable conditions. On the other side, great apes are or evolutionary cousins, we know they harbor intelligence, we have communicated with them. They are so close to actually being a intelligent species, I just can't see them being locked up in a cage and used, I wouldn't want to be.
So it is an ethical mess to me, such a fine line.
I don't care much for the slippery slope argument, because some may say a chimp is the same as a rat or a worm, but until that argument exists inn reality lets not address it. Thus is about apes, not mammals or life lets cross bridges as they come, save the rat debate for the day that they try to say it is unethical in the legislature.
The slippery slope is a sorry reason to not grow. Think about it when it is used against you, it is preposterous.