Ok this is going to be just my pillled up thoughts after 15 days since I received MKII, I didn't bother with burn in I just plugged them in straight. Whatever change happens if any it will be very minimal.
First I tried stock S blue heart silicones and Xelastecs S deep insertion but both gave me insane ear fatigue. In the next couple of days i was rolling between those tips and some other I have on hand, Symbio peels, Spinfits CP145, 155, starlines, and various no names.... All in M (my usual) size with shallow fit, but deep enough so I can get good seal and isolation.
Deep insertion is out of the question for me, max I can take is 30 min before it gets unbearable. I have ordered kbear 07,cp100, cp1025 all in S-M so we'll see... For now I use cp145 and I'm very happy with the result.
Btw No way I'll go custom again.. Thats just not for me. I had very bad experience with Thieaudio L4. How they sounded aside, I don't like the feeling when inserting them, always worrying about earwax. But after a while no issues with ear fatigue though.. Still I'm not ready to commit to ciem probably ever.
Sound wise, clearly MKII is the best iem I own and tried. Other what's in my sig I have owned Monarch MKII but in my case it's either I got the lemon unit or Monarch MKII is the most overhyped and worst iem for its price. Anyways I don't have much experience in this price range, and now with Mest MKII I don't want to go higher at least not anytime soon.
Frequency response of Mest MKII sometimes is fantastic and sometimes not so much. Depends on the type of music I listen to. I'm talking about high mids, sometimes I feel they are too recessed then I have to use EQ for 2-3 db. Then again sometimes when EQed I get like honkey sound. Atm I'm experimenting and for the most part I guess it's just brain burn in, I have used to the response of Monarch and S8F, both have more 2-4k energy.
Atm I cannot directly compare MKII with Monarch, because 2 days into owning MKII, my Monarch decided to break down so now it's on the way back to Linsoul for repair. But from memory i believe Monarch for my taste have better mids and treble tuning, it's just so buttery smooth and perfect. But I will have to compare them whan I get my Monarch back.
Other than that I have nothing to complain, for my tastes bass and whole FR is great, technicalities as well. They can keep up with most demanding prog, technical metal... very well I like them very much, no purchase regret whatsoever.
I still need the mileage, tip roll and my Monarch back for final thoughts.
Btw I use Xinhs 8 core graphene cable. Someone measured both stock and this one, surprisingly this one measured better than the stock. I can't remember figures now but that was good enough for me.