[4bpp]

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.

[foresto]

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.