As with many other posters here, I was not a fan of the "get juiced up and fight Klingons" scenes, from basically any angle. I didn't really care for the fight scene in general, and the stimulant stuff just seems whacky.
However, I'm inclined to give them the benefit of the doubt here, because this sort of thing is not totally foreign to Star Trek: in Amok Time, McCoy gives Kirk an injection of something which allows him to temporarily match Spock's strength and fighting ability. It's one of the many, many "well why don't they always do that?" Things that pops up in Trek and in TOS especially, and my hope is that the long term plan here is to settle that question. Perhaps this thing has some truly nasty side effects, or it's extremely addictive; in any case there's plenty of reason not to make it standard or even permissible gear.
Branching slightly from there, it's remarkable how much sketchy stuff doctor M'benga has already been involved in. First keeping his child in the transporter buffer and then releasing her to live in a cloud, now revealing that he keeps vials of hulk drugs about his person at all times. There's plenty of grounds here for us to surmise why he is no longer a CMO when he shows up in TOS.
Which leads to the third point that's beginning to worry me about this show: we're seeing a number of character arcs which we already know the ultimate resolution to, and it's not the resolution that I find myself rooting for as I watch these characters. Spock and Chapel definitely don't wind up together; Spock and Chapel both become much more emotionally withdrawn; M'benga gets himself demoted; T'Pring finds a flagrantly sociopathic way out of her relationship with Spock. And,obviously, Pike suffers his horrific accident. It's a pretty depressing slate of events inevitable occurring to a number of characters who I didn't care about all that much before this show (excepting Spock, obviously) and have come to really enjoy watching here.
The "well we know they won't die" is an often cited rebuke for why prequels with classic characters aren't always a great idea, but "we know the general arc of their lives" is arguably more impactful. Most characters don't die during their shows, and if the writing and acting is good enough I won't care that an outcome is preordained while I'm watching. But knowing that storylines I am emotionally invested in are doomed to end badly hits me at times when I can and will actually think about it, and It's really not a good mix with what should fundamentally be an optimistic show.