I'll be brief. This particular adaptation failed. Hard.
Either they tried to adapt everything in a short timetable, or the opposite, but J.C.Staff cut too much of the novel content in the process. I would prefer it if they decided to animate less in this season, but with better detail, instead of rushing through the story abandoning valuable pieces left and right. Story 4/10.
Characters' inner thoughts are omitted, some characters were not even introduced and just appeared with no backstory. As a result, their motivation is unknown, their actions seem irrational and forced. Even an off-screen narrator would do, like when Touma narrates about his situation.
Why not give Hamazura the same opportunity to introduce the viewer to his situation? 5/10.
And it's all too rushed. We should have had 4-5 episodes dedicated to ITEM alone before Fre//nda happens. Because like this we feel nothing, it just doesn't faze us. The constant jumping between POVs is also not appreciated, not with THAT pace.
Art is passable (6/10), but fights are pathetic. Special effects are just... total trash. Accelerator vs Dark Matter was supposed to be epic. It was instead a short sequence of bad choreography mixed with garbage CG (especially Accelerator's attacks - wtf is that black thing?). And then... the conclusion of the fight happens off-screen on top of that. Other fights are also bad. Mercs and drones that shoot bad CG lines of yellow and never can hit any named characters (who stand still and scatter only AFTER the shooting starts), constant speaking in the middle of the fight, characters teleporting (not via ability, but through scenarists' oversight) all over the city...
The sound is not praiseworthy either. Touma's canceling sound was changed from glass breaking to... something. It just doesn't suit the situation. Music is fine but nothing fantastic. The rest is normal. 5/10.
While original story and characters are good, in this adaptation we can't see any of that. Enjoyment 3/10.
So, overall - poor. 3/10.