I prefer it spelled as Bryn/Brenn/Brin for some strange reason.
I don't like that this is supposed to be the feminine version just because of the extra N, its beginning to look girly to me, despite sounding unisex all-around. Its a kind trick.
Brynn is a nice name though, I'd use it as a middle name.
https://www.behindthename.com/polls/356294https://www.behindthename.com/polls/356351https://www.behindthename.com/polls/member/181370