They used to have a page wittily named "feature matrix", which made it apparent that only Element was really kept up to date, with other clients missing features ranging from channel search to embedding images. I don't know if this situation has improved and whether the original page still exists somewhere.
Several of them have been reporting improvements over the past couple years in the weekly Matrix development blog, and I know at least one of them has both search and embedded images. You might want to have another look some time.