If you can live without the dedicated GPU for the media center, you can get an Intel CPU instead, which have QuickSync for media transcoding. It will use a fraction of the power a dedicated GPU does with the same workload.
That's likely the place you can gain most power effeciency.
Thunderbird is my primary email client, so better dark-mode is a welcome addition.
UI couuld use a lift in general, but I don't mind it looking a bit dated. As long as it does what it should and does not eat all my systems resources while doing it.
It seems to use the 2.4 GHz wireless frequency, which is notoriously overcrowded with wifi, bluetooth and all manor of wireless connections. Any of these will lessen the stable connection length. So do you use other wireless devices in the area between your mouse and the PC?
Might deviate a day or two if issues arise, but like 95% of the time it's spot on.