My 32's are Grand Bois and carry ~65PSI and the 38's are Soma (panaracer, and very similar to the Grand Bois) with similar pressure.
Rolling resistance feels higher but my speeds and times don't show any drop on my workout rides yet. In fact my first loop on the new 38's was a new best. I'm sure there's still some difference but I bet the softness makes them feel slower than they actually are.