D-ring, most everyone is familiar with. Hard to put on with gloves on. Possible extra strap flopping around if you don't have a button to secure (like Arai). Hard to take off with gloves on. Easy to lock to bike.
Ratchet is easy to put on & remove with gloves. No extra strap flopping around. Difficult to lock to the bike.
I got a Schuberth in the late fall, my first helmet with ratchet. I must say, I really like it so far. When I switch to my other helmets I do miss the ratchet most of the time. But when I get off the bike & want to leave the helmet on it, I miss the D-ring. If you have a ratchet & a case with enough room for the helmet, it's a great combo.
I'm sure I'll prefer a ratchet on my next helmet purchase.