Some musings:
Hoopa-U is all the rage now, and it's interesting to see how people's perceptions of it have changed since its introduction. When Hoopa-U became legal, players wasted no time messing around with their new toy. Players were quick to slap on a LO and have their fun with its powerful attacks and large movepool. After players started to use Hoopa-U for a while though, its hype started to die down. While LO sets were nice and all, players were turned off by how quickly recoil took its toll on Hoopa-U's health and wore the thing down between SR and other residual damage like sand. This affected its wallbreaking abilities and quickly placed Hoopa-U in range to be killed by things like Latios. As the metagame evolved, this started to change as players discovered new ways to abuse Hoopa-U. Band sets made an appearance, eventually followed by Specs. Both CB and Specs lack the recoil issue, pack greater power, and don't have to split EVs in Atk and SpA like LO does. Specs variants in particular are quickly gaining traction and becoming known as Hoopa-U's most lethal set. Unlike CB Hoopa-U, Specs doesn't mind burns as much. Special sponges are in less supply compared to physical ones like Lando-T, and teams generally don't have much to take crazy special hits like a Specs Dark Pulse. Combine this with Psyshock to break the special sponges Dark Pulse can't take down, like Chansey, and you have a Pokemon able to deal insane damage from both sides unlike CB. Finally, Dark Pulse has no drawback unlike Hyperspace Fury's defense drop, and this is useful to avoid being killed by things like Scarf Tar's Pursuit. Add the several other sets Hoopa-U can use to the picture and it's easy to see why this thing has become so dominating and unpredictable lately. Overall, Hoopa-U is a very dangerous and strong Pokemon currently. The monster performs well versus the majority of playstyles and can usually grab a kill or more during a battle. If it doesn't, it's very likely to have severely weakened something before dying. I am interested to see if the hype continues or dies down in the coming weeks.
On the topic of Hoopa-U, I find U-turn + Volt Switch to be a good way to bring out its full potential. Hoopa-U really likes being brought in for free, and I think this is something people have grown to realize. This is a reason things like Rotom-W and others are commonly being seen paired with it now. Being passive is something to be very cautious of in today's metagame, and using strong attackers alongside U-turn and Volt Switch is a good way to apply pressure and maintain momentum on your side in general. Things like Torn-T and Lando-T having access to U-turn and being overall good Pokemon contributes to this. This strategy fits naturally with the bulky offensive styles currently running rampant.
As far as other observations go, Tar and sand in general is popular. Aside from how valuable Scarf Tar is to trap Hoopa-U, its abilities as a supporter with SR and Chople have gained recognition during the past few months. Being the premier sand setter to use alongside offensive powerhouses like Exca is also of note. I have been seeing CB variants popping up more here and there, and these are cool to wall break and trap growing trends like Mega Latias more effectively. Tar is probably a reason things like Gengar have seen sharp declines in usage too.
Speaking of Mega Latias, it's so popular. It has been everywhere over the months, and it's easy to see why. Its typing, impressive bulk, and good speed are all valuable to help teams deal with Pokemon that aren't very easy to cover, such as Keld, Char-Y, Thund-I, and many others. Blanket checking so much in one slot is really valuable for many builds. It helps that Mega Latias isn't passive either, possessing a good deal of power and coverage between Ice Beam and Thunderbolt to threaten offensive teams rather well. Something interesting I've found is the debate between Thunder Wave and Reflect Type. I think the latter is starting to become more and more appealing now to help Mega Latias win many more 1v1 matchups (Heatran, Ferro, Bisharp as examples).
Lando-T remains the bulky ground of choice. Intimidate, U-turn, SR, SD, and the ability to check things like Exca and Char-X while avoiding the passiveness of Pokemon like Hippo is great. It has been given the nudge over Chomp for a while now, and is a reason offensive variants of the land shark are generally favored now. Other trends like AV Tangrowth and Amoonguss also continue to be effective and help teams cover a wide range of threats, such as Keld, Mega Diancie, and Loom. Pokemon like Clefable and Keldeo are still as good as they've ever been too.
Any other observations you guys have noticed or thought about lately?