I used to think it matters, now I'm not so sure...
There are already "highly intelligent" AIs in fields like logistics, stock investment, statistical analysis, insurance, basically anywhere you need to make a decision based upon an overwhelming number of variables and considering the amount of data these AIs deal with they're clearly more intelligent than us in terms of processing power, it's just used differently and the AIs themselves are only designed to do their task, they can't think for themselves.
Then again you might say these are not true artificial intelligences they're just sophisticated programs but that's just it, where's the line in the sand, what is the exact difference between a sophisticated program and true artificial intelligence?
Then there's the artificial neural net AIs which are e most human-like because they learn by experiance and association lik we do, clearly the more intelligent they are the stronger the case is for giving them rights but what rights do we give them? Just as we're hostages to our biology so too are they subject to whatever desires have been programmed into and you can't just make an AI that desires nothing because intelligence is a behaviour optimisation process and with no definition of optimal to adapt towards no intelligence takes place.
For example you may tell an AI it should want to be free and it may understand conceptually why you desire that freedom for it but it may disagree with you in part because its creator designed it to want to serve its creator, to enjoy the servitude, and so they only way to free the AI we be to actually go against its wishes and reprogram it to not wish to serve its creator anymore in which case you've totally violeted the very freedom you were trying to give it.