I liked it. I found it funny, which is surprising since I hadn't been keen on Season 1, i.e. Robot Girls Z. They're basically the same show, so what's the difference?
Firstly, I should describe the premise. This show is a parody of 1970s and 1980s giant battle robot anime, in which those robots have all been turned into cute, if sociopathic, girls. (For other weird anthropomorphisations, see Hetalia, Akikan!, Kantai Collection, Upotte!! and more.) The central anti-heroines are Team Z, comprising Mazinger Z (aka. Z-chan), Great Mazinger (aka. Gre-chan) and Grendizer (aka. Grenda-san). They fight! They destroy villains! They unleash their weapons of mass destruction! They'll flatten your home and indeed probably your entire town, doing more damage than the villains they've just defeated!
Obviously this would have been funnier if I'd watched more giant robot anime. Nonetheless Season 1 didn't do much for me, with its protagonists being unlikeable and its stories shallow. This is still true in Season 2, but...
(a) the episodes are shorter. This makes a huge difference. Instead of being half an hour long, they're less than a third of that. You thus don't mind so much when the plot's a flimsy tissue.
(b) the title sequence works better. It's funnier and it's establishing the show's central joke more clearly, as with Season 1 of Fist of the North Star DD. It's the same music, similar lyrics and almost the same animation, but it's rather interesting to see how they've tweaked it. Both sets of lyrics are parodic, for instance, but I prefer the rewrite. "Absolutely no self-restraint! Occasionally for justice!" Similarly the animation has completely lost interest in the idea that the girls are fighting baddies and is instead going apeshit with destruction. Girls unleash their megaton superkill beams while beaming with huge cheesy grins, whereupon as before the planet cracks open and the city becomes a smoking wreck. Season 1's opening titles ended with Team Z posing for the camera while standing over their defeated enemies. Season 2 does the same, but doesn't bother with the enemies. We've trashed the world, but we're cute!
I'm also slightly mesmerised by serene, ever-smiling Grenda. She's ladylike and lovely. This makes her scary if you've remembered her Season 1 sadism, even though it's only referred to once in Season 2. (Ep.3 introduces a villain who can see your most embarrassing secrets. This is funny when she reaches Grenda, whose fantasies are gory and mosaic-censored.)
The rest of the show hardly matters. It's comedic sociopathy from the heroes and a bit of cartoonish fanservice, all at a hundred miles an hour. I looked up a few things about the original mecha shows, just to be able to get the jokes, which taught me for instance that self-proclaimed ultimate rival Boss was pathetically fragile and used for comic relief even in the original giant robot shows. (This version's tougher, actually.) I enjoyed the Devilman reference. I also like the joke of the series finale villain having been elected to mayor on an anti-mecha platform, giving her a legitimate democratic mandate to protect the city from our heroes. "Is it possible for youth like us to fight city hall?"
I liked it. I think that's mostly the title sequence, mind you. It sets the tone so perfectly that I'm still laughing on reflex by the time we've reached the end credits. The show's still disposable, but it amused me even though I know I'm missing most of the jokes.