Where is everyone? Nobody playing since the patch?
I played a bit last night, my hot take on the new swarm hosts is: they're really good as individual units, and really bad as part of your army.
The good: the new locusts have had their DPS increased from 15 -> 20, and they pack a major punch. With 5 SH with flying locusts, I sent them over a cliff into a Protoss natural and the ten locusts targeted down the nexus (albeit with no static defense or army present) before expiring. The SH is a lot more mobile than before (30% faster, don't have to burrow) so you can hit and run with your locust waves somewhat - it is pretty cool for harassment. I had some hellions chasing my SH down in one game yesterday and I spawned a locust wave on the move and killed most of them plus two thors and a tank that were a-moving along behind. It feels pretty great to not have them just die instantly when cornered like before.
The bad: good lord, 4 supply and 200 gas is A LOT for a unit that spends half the game doing nothing. It's a minute between locust waves but locusts only last 25 seconds, so even with perfect efficiency, a small number like 6 swarm hosts still represents 24 supply of your army (not an insignificant number!!) that is literally useless 58% of the time. I had one game go lategame against Protoss and I was struggling a lot with figuring out what composition to make, he had stalkers and colossi and high templar with storm and some void rays, and my comp was...ling-hydra into roaches (once colossi showed up) into corruptors into brood lords? It felt very awkward, because any Zerg army that includes a large quantity of roaches is worse and worse as the game goes on, but at the same time we can't exactly do much else with that supply and be cost-effective with it. Maybe we make roaches because we lose the smallest amount of resources when that supply dies. I didn't even make swarm hosts that game, which kinda leads to the problem with the new design: there's no point in making them unless you're already ahead, at which point it doesn't really matter what you make. If you're behind in a game, dropping 4 supply and 200 gas on a swarm host that only spawns locusts once a minute is a terribly dumb move. Like, you can sneak around and shoot them over a cliff and snipe a base, and then your opponent a-moves and you die because you have all that wasted army supply. If you're even with your opponent, it's risky. If you're ahead, cool, you could probably have just made brood lords instead for the same effect.
Basically, it's great for trolling bad kids on ladder. I had numerous people last night who were like "wtf there was a patch?" or my favorite, "WTF WHEN DID I START PLAYING LOTV". But I would be surprised if we see them in high-level ZvP or ZvT ever again.