I'd aim the spotlight down from a higher angle (notice how the top of the sofa cushions are dark - not too realistic, i think).

Good that you used a Quadratic spot indoors! You can turn off the spotlight influence on the floor and/or make the floor darker in the Material Editor (the ambient slider will have the most influence on the GR indirect light reflections).

Agree with Bruno's ideas on changing the warm color cast.

It's not a bad render - doesn't have those "too light" corner seams that one gets from too much GR gain.

If you find soft shadows or other areas getting "grainy", try the new soft shadow smoothing feature in the Light & Shadow Editor - much faster than Object anti-aliasing. But you might have to enable a bit of soft shadow (1%) to turn that feature on.

You might want to check the ratio of your sunlight intensity Vs spotlight intensity. For a daylight scene, one would expect the sunlight to be noticably brighter than any artificial lights (unless you intend a "restricted lighting" look. Also the scene dynamics, drama and 3D depth feelings will suffer if all the light sources are nearly the same brightness.