Well, since this is essentially an entirely "new metagame", Weather plays almost completely differently from in 6 v.6, as there are no bans on SW+Drizzle; You can only bring 3 Pokemon to each match, so it's fairly pointless to stock your team with more than 3 of one type (such as 2 Grass Types and 4 Water Types on a single Drizzle team). This also makes threats such as Excadrill far more potent, as you must sacrifice 1/3 of your team if you wish to sacrifice something to bring something else in safely. I could go on and on about how SB Blaziken, "Dropped Clauses", ect. ect. effect weather usage, but I'll leave that for later.
I myself personally find sun to be very effective; I've tried rain, but it seemed like most of the (good) people I faced had a good Rain counter (such as Abomasnow or Zapdos), while less people seem to be prepared to face a Drought team.
Anyways, feel free to talk about what weather you believe is weakest, strongest, what works and what doesn't in any type of weather.
I myself personally find sun to be very effective; I've tried rain, but it seemed like most of the (good) people I faced had a good Rain counter (such as Abomasnow or Zapdos), while less people seem to be prepared to face a Drought team.
Anyways, feel free to talk about what weather you believe is weakest, strongest, what works and what doesn't in any type of weather.