The HE-500 signature is very different from both the LCD-X and the LCD-3. I think the Mjolnir pairs better with the LCD-3, since the forward brightness of the amp tempers the lush thick sound of the LCD-3s. To me, the LCD-3 is a more mid-centric phone than the LCD-X. The M/G is still very nice with the LCD-X--especially if you like a a very spacious, neutral, and lean sound. The HE500 with the M/G is bright and somewhat harsh to my ears.
and i agree with ur point on HE500, sometimes it will feel harsh and bright which made my ears fatigue, but i still miss the nice ''vocal to the face'' sound. thanks ur opinion, guess i will still go for Lcd-3 since i don't think i will change my Mjo/Gun combo, at least not now. :)