Flux and kinematics maps of the z = 2.19 galaxy ZC406690, comparing LGS-AO integral field spectroscopy between SINFONI (top) and ERIS (bottom). In both cases the data have been lightly smoothed. Far left: full 10 hr archival SINFONI flux map. Top: 90-min sub-set of those data (showing flux, velocity, and dispersion), taken in reasonably good conditions. Bottom: 90-min ERIS dataset taken at R ~ 10 000 in less optimal conditions. ERIS data were taken early in commissioning before the AO system was optimised, but already outperform the equivalent R ~ 3500 SINFONI dataset, and show all the structure visible in the full SINFONI integration.