There are three features that the LynxTWO has that the L22 does not:

1. SMPTE time code reader and generator.
2. Composite video genlock synchronization.
3. More analog IO channels (Model A has 4 ins/4 outs, Model B has 2 ins/6 outs, Model C has 6 ins/2 outs). The L22 has 2 analog ins and outs.

Other than that, the feature set and audio quality are identical.