I can contribute with direct experience. I was 40 with 300 hrs when I was offered a 737 position after passing selection.
I don't think there any advantages to being older. It is difficult for me to suggest that there were significant disadvantages. I did fail one interview in vague circumstances. I think most people who have failed interviews with this business' practice of not providing feedback would feel the same.
Regardless, I definitely got the impression that during the assessment and selection processes that I passed there was no bias one way or the other. I was reliably informed by those organisations of a couple of airlines that outright would not consider me due to my age.