It's not a fun fight, and many fights have ended in vote abandons because the three strike rule and the single healer is just too punishing.
It's not the speed of the mechanics, its not the lack of telegraphs, it's not even the dodge and no healing of the second phase. It's the fact that three deaths and you are back to start, and its incredibly easy to get those deaths if the healer is the one dead.
In practice it really requires perfect play over 8 minutes,very similar to Feast. And it's not a slow fight, which can intensify this. There is no backup, unlike ex or savage content, so if the healer goes down or is stunned, you may not be able to recover in time. And at the last phase, the healer loses most of the power to compensate for mistakes.
This leads to a very frustrating fight. It's not a matter of skill; I have done runs with people wearing not a few diamond pieces, meaning they do savage. They suffer too. It's just you wind up removing a lot of what makes hard fights in this game tolerable, but you gave us nothing to compensate. No dodge roll, No real debuffing or support class, not many classes who can also esuna, etc.
If you use this as a pattern, it's not going to be good difficulty. And we see people reacting to it by ditching the traditional party and abusing tank's durability, as well as telling others just to wait to outgear it. I've spent a dozen runs watching people just vote abandon at 30 min or more because the fight requires too little mistakes for an MMO. Yes I know MH may have this, but MH also built the game around it and eases you into it over a LOT of hours. This is the first time where the run can really reset so quickly and easily.
I feel like if you want to make difficult fights, you need to really do so within the confines of the game structure. You can't just slap on a requirement for perfect play like that, and end up with imbalanced between jobs as it is. I've seen DPS get one-shot, while tanks eat chains of attacks. People here are doing the same mistake that led to HW; assuming that everyone likes the fight or finds it fun when it's not as cut and dry. Especially in the first week of content, where we don't know how many people will stick with it or not. I already saw 25 min as a DPS queueing for it, only to turn to healer and instapop.