I rarely get to use blended learning although I think this is preferable. I teach fully online distance learning courses. Most of the students live within commuting distance to school and many have on-campus courses as well. Although students say they want to get together in person, there never seems to be a time when more than 1-2 students out of a class of 30 can come to campus or even meet online synchronously.
My colleagues who have on-campus courses have more opportunity to use a blended format. There is a continuum from on-campus only to distance only.
Some instructors who have on-campus and distance sections of the same course encourage students to fit in where ever they want. On-campus classes are well attended at the beginning of the semester and for some difficult material presentations and problem-solving sessions. By the end of the semester very few from either section come to class, but the completion rates for both sections are much higher. This says a lot about the power of blended learning to provide students with the learning opportunities they want and need.