It's a shame that there are no 3800X reviews yet. The 3700X seems a bit constricted by its low TDP, so the extra 40W of its sibling could make it the best choice.
Nah, power efficiency rules the day.
I'm sure within the next decade, at most, computer parts will start to be a strong target of power consumption regulations, specially GPUs and servers. So better start to appreciate it right now!