What source are you using? If your source isn't already pretty good not sure it is worth going to the HE500 without improving source first...
Anyways, mine is still shipping to me, so I have no personal experience, but with the gain on this it should have no trouble driving most orthos that aren't the HE-6. The Headphonia review virtually raved about how good the Glacier was with the LCD-2. I should get my Glacier late this week/early next, if nobody else has posted before then I will let you know how it is with my HE-6 and LCD-2.
I'll be alternating between using my laptop with poor internal DAC (currently connected to a Schiit Asgard) and my Sansa Clip Zip (my main reason is portability with the Glacier). So tempted to get this but due to lack of reviews I am still hesitating to pull the trigger.
Hope you post your impressions soon. Still amazed that there are claims that these amp/DAC can drive the HD 800 and HE-6 to bearable levels though..