I have both. My road shoes are a 44.0 and I wear them with socks. My Trivents are 43.5 as I do not wear socks and, given the change in volume, I found the 44.0 in the Trivent too big for my tastes. I really wanted a snug, sock-less fit for the Trivent.
I had the road shoes for a year before I got the tri shoes. Love em both. I wear the road shoes a half size bigger because I wear socks. I wear the tri shoes without socks.