I've posted impressions of the lyr and the he400 many times. Although the he400 is easy to amp for an ortho, it will scale up modestly with better gear. The lyr gives it a smooth lush sound and makes the bass even better....more dynamic. Of course this change will vary based on the tubes that you use.
If I was only driving the he400 and other easier to drive hp's, it would be hard to justify the expense of the lyr. If you have other hp's that need the power of the lyr it's a very good choice.