The Eheim nozzle pictured above constricts and speeds flow from the outlet. It directs a fast-moving, narrowly-focused jet of water which, as you say, will not cause much surface movement. A constant jet with one focal point might have some unexpected consequences.
The concept of the
ADA Lily Pipe which flares out like an
arum lily, rather than constricts inward to a narrow nozzle, produces a much gentler flow which also does not cause much surface movement.
If you use the standard 1/2 or 5/8 Eheim outlet you will find it produces a fairly focused but gentle flow. I use and prefer this form and think of it as the 'cheap form' Lily Pipe - rather than spraybars.
Andrew Cribb