No Knobs?
"there are only limited tweaking options on board, with an on-screen slider each for bass and treble and a bass correction setting that beefs up the low end for smaller speakers "
With decent kit there shouldn't be much of a need to tweak, maybe just the once but then leave the bloody thing alone. Most audio stuff could do with a 'loudness'* switch as it's rarely turned up to drive things properly but that's it.
Want one.
*a loudness switch? burn the heretic!