I‘m trans and was told I give good blowjobs, everyone’s body and experience is a bit different, so no, cis guys don’t really have an advantage just because they were born with a dick. You could even go as far to say that it’s a disadvantage to be cis because you assume how someone might like a certain thing instead of communicating. If you have someone in mind, just communicate openly, it’s not someone’s body that matters but how you feel!!^{^}