So I have owned the LCD-2 rev.1 and currently own the HE-500 along with the LF339. To my ears, the LF339 did not have much synergy with the LCD-2, but work tremendously well with the LF339. I also own the V200, which worked very well with the LCD-2 and works well with the HE-500. Best combination to my ears is the HE-500 and LF339 (With Tung Sol 5998 and RCA 5693 tubes). It does
every genre justice, and has an extremely deep, impactful bass. There is no sense of harshness on the treble with this combination, if you may be concerned about that, and vocals are as beautiful as ever. I will say that I prefer the HE-500 over the LCD-2 (I feel like the vocals on the LCD-2 are portrayed as somewhat far away), however my main issue with the LCD-2 was comfort (something you may want to consider). Though they both have a strong clamping force, the HE-500s force is allocated around your ears, and the LCD-2s force is allocated closer to your cheekbones. The pressure to the cheekbones is just too uncomfortable for me, but I can deal with and wear the HE-500 for a long time.
In essence, both are wonderful pairs of headphones, but if comfort is a biggy for you, I'd recommend going HE-500. Also, with your setup (assuming you own the LF339), from one owner to another, trust me, the HE-500 is
excellent with the setup I listed above
Oh on a side note, while I spoke about the LCD-2 rev.1 (and have never heard the LCD-2 rev.2 or LCD-3) If pressure on your cheekbones is going to bother you, it's not going to change from rev 1 to rev 2 or LCD-3, as they're all designed to fit on your head the same way. Can't really comment on synergy for the LF339 with the rev.2 or lcd-3, but my bets are that it will
not synergize as well with the LF339 as it may with something like a V200.
Yep, very well spoken.