I've had several 007s, a mk1, an early mk2, and a late mk2, what people call the mk2.9. I'll talk about the mk2.9 since I assume that's what you're asking.
It's a tricky set of headphones, capable of world-class sound but needing some modding and EQ to get there.
First, you're gonna need a powerful amp. Don't even think of using a 007t or 700t, it's simply not powerful enough. You will get very little in the way of dynamics, and you will come to a point where raising the volume does not make the sound louder but just harsher and more compressed. The 700s will be a lot better, you'll have more usable volume and better dynamics but you'll still be leaving a lot of performance on the table. Ideally, you'll want a KGSSHV or Carbon, or a Blue Hawaii or similar level of amplifier.
Second, the bass port mod is generally recommended as it tightens up the bass and clears up the midrange.
The tuning out of the box is a bit questionable. It's not bad, you have a reasonably tight and punchy bass, a warm midrange but with a nasal tone, and a treble that's slightly wrong in tembre and definitely quite bright.
This is fixable with EQ, and the 007 responds very well to it. You can knock out the nasal coloration and straighten out the highs with only a few adjustments. But you will need an amp that can play above normal listening levels without issues, which once again steers you towards a KGSS or similar amp.
Do all this, and you end up with a headphone that plays in the big leagues, with world-class resolution, solid dynamics, excellent imaging and front to back layering, while at the same time sounding coherent and natural.
Of course all of this begs the question: why should you have to tweak, EQ, and spend thousands on an amp for a $2k+ headphone when there are others that will perform well out of the box?
Well... that's really up to you. If you're the sort that will tweak and EQ anything you get your hands on anyway, then the 007 will get you to a higher level of sound quality than just about anything else out there, so you might as well. But if you're adverse to doing any of this, then there are probably better options.
Incidentally, the earlier mk1 didn't require you to do any of this and was better tuned out of the box. Sadly, they're getting rare and hard to find. You want to score an early 70xxx serial number version, those are the best, but VERY rare and also a bit fragile - the cable did not have appropriate strain relief at the connection to the driver, and it often goes faulty and intermittent. So be sure to ask if there are any intermittency issues, or channel balance issues, before picking up a used pair.
