Yup, girls tend to be more complex to please, and take longer.
There's a lot more looking and analysing of sounds and body motions to figure out how to proceed.
In my experience, it's rarely happened that a girl could not please me (although i rarely climax from it at all), while i've had much more trouble getting the girl into mad-sex-mode by oral stimulation. But maybe it's just never been my specialty- i'm open to suggestions tho