I would say it's worth it if your music genre is more focused on vocals and instruments.
For music listeners like me who prefer the upbeat hip hop and pop songs, the HE-400 does better, HOWEVER, sometimes i like to hear the vocals more forward and separated, which is where the HE-500 comes in. Thus when i want to have fun flare, i'll use the HE-400 and when i feel less energetic i'll grab the HE-500. That is why i chose to own both. instead of selling one off.
The HE-400 comes very close to the HE-500 when you're using a high quality wire. The bass and treble Improves greatly, so you're getting the best of both worlds.
The HE-400 is already bass heavy, so with the stock cheap $1 op amp (NE5532) the bass is very boomy and harsh when using the HE-400. I'm pretty sure they were made to be swapped out right away, or for those computer gamers who knows nothing and think that sound quality requires a "fat" bass and nothing more. This boomy bass helps add a little more realism in games, specifically for gunfires and bomb sounds. I've found that the running sound, closing a vehicle door, etc sounds extremely fake with the NE5532.
Muses has already been launched, if you go back 3-6 pages, one of the ASUS members gave a buying like, you'll also noticed that i recommend buying the Original Essence One and Muses01's separately as it is cheaper. Grab the MUSES Edition if you ever feel as though you'll be using In Ear Earphones with them, the MUSES Edition has a gain switch so it will not out blast IEM's.
Thanks for the reply.
I also have a wide taste in music so I'm still no closer to a decision as far as HE-400 vs HE-500 is concerned lol
I'm really tempted to get the Essence One and then upgrade the op-amps to Muses01's but I do have some IEM's so having the gain switch might actually come in handy.
Really hope they will soon give a UK release date for the Muses Edition, hopefully it will be around the same priced as in the US and not inflated for the UK market.
On cables for the HE-400 do you have any recommendations.
BTW I did read this whole thread and other threads on the HE's so I'm on information overload
Edited by 4Real - 1/5/13 at 8:37am