I am torn between KRK and Yamaha HS series. Any recommendations?
I got me a set of HS5 just a few weeks ago. The only con I found against them was that they have a weaker bass response below 70 Hz or so. I still opted for them because the high and mid fetail was but pleasing and the slight lack of bass actually does pretty good in my small and completely untreated room. As I saw/read in the reviews, this bass issue was mostly apparent in well treated room, so for me it sounded like and ideal scenario. I’ve really nothing to compare them to (only had quality hi-fi stuff, but no reference monitor), but I am glad I got them. I think they’re excellent for their price and my purposes (home recording and quality listening experience).Discovering new stuff in songs that I’ve been listening to for 25 years… 
Or for example I never heard the speed car in the beginning of Black Ice from @kiko 's Open Source… Hearing it made me realize that it might be a speeding car hitting a patch of black ice and the very first guitar part is how it’s sliding and rolling around and then the next guitar part might be the sirens of the ER car. Oh and the Yamaha has a white woofer and backlit logo, which obviously make them sound better… .
I have Kali LPs and love them. Sorry no experience with the others you mentioned.
I have a pair of 8” Kali’s as well. Great speakers. Yamaha make some nice stuff. I don’t think you’d have any problem if you went that route.
I tried KRK, pretty good! The problem was, I couldn’t mix with them because I couldn’t get used to the way they sounded and tried to make the mix sound like I hear the music, which was impossible.
Got some Samson Rubicon with related subwoofer, which were pretty good as well, though a bit “flat”.
Then I bought the HS80M and combined them with the Rubicon woofer, which now works pretty well for me.
I first had installed sort of an A/B and A+B switch to be able to mix with both pairs, the Samson and the Yamaha. After a while I recognised, that I wasn’t using the Samson anymore so I uninstalled them.
Even got a second of the Samson Rubicon woofers now, still need to try to combine them some day as a stereo system.
I’d put it this way:
Compare different sets of speakers in your room, listen deeply into music you already know. If you feel fine with the sound and if you hear more details then before this is a good indicator that you have found something usable.
If not, consider to take care of the acoustics in your room. If it sounds bad, you won’t have any benefit from the best monitors.
Move the speakers in your room and compare the sound. Maybe you’ll have to rearrange you room completely (can be pretty annoying).
Compare as well with good mixing headphones. If you can’t afford to make your room sound well at the moment (effort and money intensive), consider to work with headphones and spectrum meters for now, which works fine as well for a beginning.
And of course: Always check your mixes with as many hi-fi’s as you can.
Hope this helps!!