Between the almost annoying seriousness of 2001 and the irresistible madness of Dark Star, Silent Running is in an very difficult spot where it's almost impossible to win anything beyond honorable mention for trying.

But once you've sat through Tarkovsky's Tokio driving sequence in a cinema those three all seem kind of superficial (my opinion, and probably mine alone. And I'm not sure that it would survive a re-watch of Solaris, it's been a while)