My experiences and views are related to the few posts above: sound signature preferences and in-ear seal, fit, and comfort are all very subjective.
I own the Monarch MKIIs (which I love) and was looking to upgrade. Based on the availability in my city, my budget, research, and reading of various forums I had zeroed in on the 64Audio U12t. Everyone was raving about them, and I had 99% made up my mind that I would like them as an upgrade. When I went for my pre-purchase listening session, I tried the 64 Audio lineup while A/B listening to my Monarch MKII as a reference. I did this to try and understand how much of an upgrade I was getting. To my surprise, I didn't like the 64Audio U12t. To me, it didn't feel like an upgrade over the Monarch MKII, and more so considering that it was 50-60% more expensive. I give full marks to the MKIIs for punching above their weight! I then listened to the 64 Audio Trio and absolutely fell in love with it. I thought that this was an upgrade that indeed justified the extra money I would be paying. I also realized that maybe I personally prefer hybrid IEMs more than pure BA ones.
My point is that while we share our views, opinions, and experiences, one must always try and listen to gear before buying it. In my case, had I gone with the majority opinion (u12t), I would be suffering from major buyer's remorse right now. Thankfully, this didn't happen. We all will have different opinions and views based on our personal preferences, likes, and dislikes and hence may not always understand or be convinced of someone else's choice. This is ok!
One more thing- out of the box, I found the MKIIs stock ear tips too large for my tastes. Even the smallest size tips felt too tight and uncomfortable after 20-30 mins. I upgraded to the SpinFit W1 Silicon Eartips and found that the seal and comfort improved a lot. It was like a night and day difference for me and now I am enjoying my MKIIs to the fullest! My 64 Audio Trio of course complements them extremely well!