Places like HeadRoom or Audio Advisor offer 30 days money back if you're not happy. You can hear them with your own gear and if they don't sound good "to you" just send them back.
I've not found the HE-400's to be "dark sounding" like some have said nor bright/harsh in the treble as others have stated. Now it may be that the Lyr and or the tubes I'm using just work well with the HE-400's but in my system they sound pretty balanced and a powerful bottom end that outshines other can's I've heard.
After all I'd read I was sure that I'd give the HE-400's a listen but then I'd most likely send them back for the HE-500's...now I'm pretty sure that I'm keeping the 400's.