Six episodes is about the right amount of Saiki K for me. I can watch that. It won't drag on and on for months, which had been a danger with both full 24-episode TV seasons since this isn't a show with a plot, or indeed any real purpose beyond gags.
As usual, Saiki is a pink-haired, cynical, sardonic teenager who thinks the world is boring and has almost every possible psychic power. Super-strength? Yup. Rewinding time? Yup. Basically, he can do anything and can't be threatened by anyone. He'd kill all drama if this were a drama, but instead it's a comedy with Saiki as an endless source of unspoken snarky put-downs. (We can hear his narration inside his head. He's extremely rude about his idiot friends, but with justification since they are indeed idiots.)
This is reasonably funny. About half of these episodes made me laugh and the others were all okay, except for ep.6 because I didn't watch it. It's set after the TV series finale when he sealed away his powers and I couldn't be bothered with it. Saiki K. with superpowers is funny. Saiki K. dealing with his life without superpowers was something I skipped.
My main complaint with these episode is that the girls barely appear. Aiura the gyaru fortune-teller pops up frequently, but Teruhashi, Yumehara and Mera are reduced to cameos are best. In fairness, though, this is because they're all much more sensible than their barely sentient and hence funnier male equivalents like Kaido (delusional chuunibyou), Toritsuka (pervy and can talk to the dead) and Nendo (like a big shaved ape). The show also introduces new characters and resurrects relatively little-seen ones who'd only appeared in a few episodes and so have untapped potential. There's:
(a) Satou-kun, adored by Saiki because he's the epitome of "boring and normal".
(b) Suzumiya Hii, a supernaturally unlucky girl. What's more, her misfortune will affect people in her vicinity. Try to chat her up and you might get hit by a runaway motorbike. (She meets Satou-kun, leading to a fate duel of "freak unlucky vs. guaranteed to be uninteresting".)
(c) Akechi, the boy with Sherlock Holmes observation skills who's worked out Saiki's secret and can neither shut up nor go away.
(d) Iguchi, the teacher who's nice, considerate and cursed with the face of a drooling pervert.
I liked these episodes. I like the whole show, really (although wild horses couldn't make me watch the live-action movie), but these episodes felt funnier than usual.