Welcome back, SirPleb!
Yes, indeed, the GOTM competition has survived to this day... Currently GOTM 156 is requiring everyone to play for the 20K victory condition (and everyone is complaining that I made the task too hard...
So you would be very welcome to try your hands on it and prove them wrong...
)
Regarding Civ6: I played 2-3 games single-player and a handful of games multi-player so far. It's "ok", but not that great. In fact, I liked Civ5 better in many aspects, despite the obvious shortcomings of Civ5 like the strange happiness system that makes rapid expansion very hard. But Civ5 had the best combat system of the entire series, it had very varied and interesting nations/leaders providing a broad range of approaches/strategies to choose from, and the "one unit per tile" rule requires some delicate strategic & logistic planning (especially in multi-player -- the AI doesn't seem to handle it too well...)
A few aspects of Civ6 are a bit "dull" compared to Civ5 (combat system, religion, variety of available civ traits) and others still appear unbalanced. But I see potential that with the next couple of patches it'll turn into a good game. Whether it will become "very good" remains to be seen.
But of course Civ3 remains "the best Civilization ever", as Firaxis themselves wrote on the CD box back then...!