HiFiMan HE6se V2 Over Ear Planar Magnetic Headphones Expired

The following post is only my personal opinion based off of the measurements I've viewed, a variety of reviews, and large amounts of lurking in audio forums and review sites; I consider myself fairly well informed but I am not an expert.

As fantastic of a discount as this is, I would greatly recommend the vast majority of people to avoid these headphones for serveral reasons:
First, since I know people wander onto these headphone deals not realizing these are audiophile cans for critical listening, here's some basic information: these headphones are wired only (no bluetooth or wireless connections of any kind), have no form of active noise cancelling, have extremely poor sound isolation (you can hear whats going on around you, and everyone around you can hear what you're listening too), and are extremely heavy and bulky. They are designed to be used at home with a dedicated audio setup.
Next, a very powerful headphone amplifier is 100% necessary to get even semi-decent sound out of these cans. Hifiman recommends an absolute minimum of 2 watts into 50 ohms, and many people who own these headphones recommend up to 5 watts into 50 ohms, which is an absolutely ludicrous amount of power. If you don't already have a very powerful desktop dac-amp setup, don't even think about buying these.
Another issue is that Hifiman is infamous for exceptionally poor quality control and build quality. It's pretty much accepted as a fact that if you buy a Hifiman headphone you're quite likely to be looking for a replacement in a couple years unless you get rather lucky, and that's assuming you get one that's good to begin with. This also applies just as much to their high end cans such as the He6se, if you want some examples try reading the forum thread for the he6se review on audiosciencereview. A recent example there is a guy who received three bad pairs from them in a row before they just refunded him rather than send him a fourth, and he specifically asked them to test the headphones before sending them to make sure they had no issues after he had problems with the initial ones.
Yet another reason to avoid these headphones is the value proposition: while several years ago this would have been a pretty good deal even considering the above mentioned points, there are much better value headphones nowadays, even from hifiman themselves. If you're looking for super high end sound in a similar price range the hifiman edition xs are arguably just better than the he6se, require far less power to drive, and also go on sale for ~$450 or less. Build quality and quality control are crap on the edition xs as well, but that's just par for the course with hifiman. The hifiamn sundara are somewhat worse than the he6se in most respects but are far easier to drive, and go on sale for ~$250 making them far more palatable to replace when they inevitably develop issues as hifiamn cans are wont to do. I could go on recommending other headphones, but I'll only list those two hifiman models to avoid getting too far off track.
Overall, if you already have an amp capable of driving the he6se, prefer it's tuning and sound signature over other headphones in it's price range, and don't mind hifimans quality control issues, this is an excellent price for the he6se. For anyone who doesn't entirely match the conditions listed above, I recommend you look elsewhere.

These will require an amp

You need a powerful amp as this headphone is harder to drive.