Tubulars are really nice rolling and cornering due to the shape of the tire. It’s not restricted or bound by the tire needing to hook into the rim like a clincher so it’s rounder. Plus most fo the nicer tires have a latex tube sewn in.
Clinchers have caught up so much in the last couple years with wider internal width rims however. Combined with latex tubes they roll as good but, still don’t corner quite as nice (IMO).
The major down side to tubulars is the glueing (not hard but it’s a bit time consuming) and the problems associated with getting a flat/cut out on a ride/race. You can carry a pre-glue spar but, honestly the times I had to rip one off and put the spare on it would have been easy to roll it in a corner. So I always made my home gingerly.
All in all, clinchers are the way to go for me. Much more convenient, cheaper to maintain and perform effectively just as well.