If he has a sweet nature, I can see his genetics only improving your flock. Dixie Rainbow are meat birds but also decent (though not prolific layers).
Put him over a BR hen, you'll get larger birds that lay well...a true dual purpose.
With this boy, you'll get some pretty color variety, and possibly, over BR hens, sex links.
Depending on his genetics (I see some barring but almost more Columbian), you could get sex links with your BR hens (male chicks barred, while female chicks black, or perhaps male chicks barred black, female chicks barred red, or even male chicks double barred, female single barred).
With the BR rooster over any hen, all chicks are barred.
He is a beauty.
If they are sweet, I try to keep them. It is hard to find a nice tempered rooster, and I regret those I have disposed of....the mean ones...which I've gotten plenty of...make good soup!
Lofmc