Unit #4 is being shipped to @Cotnijoe today.

Received #4 loaner today.

I might be able to answer your question in about a week. :) I'm going on an extended trip and plan on using the HA-2 exclusively with my iPhone 6 as I travel.   I finally got the time the other day to really play around with it. I can't believe how much these improve my IM-02's when being fed...

Here are my initial impressions between the two. Copy and pasted from this thread since I am being lazy :)  

I hope you like them. They are definitely more "fun" cans then my HD595's. If you want a primer on what they will sound like, read @Baycode's review. After having them for awhile, I agree almost completely with his conclusions(except for the bass and I don't have an issue with the weight)...

Awesome, I should have mine by tomorrow. Going to run my new set of ATH-IM02s on them. Can't wait! :)

Finally was able to put a couple of hours on my new cans last night. I just want to thank whoever returned these to Amazon because, as far as I can tell, there is nothing wrong with them. They definitely have a different sound then my HD595's. Going to need a little more time to elaborate...

After reading the thread I've decided to pick up a pair of IM-02s through Amazon. Going to pair them with an Oppo HA-2 and should be getting both tomorrow. This is my first IEM purchase in over three years and I can't wait to check them out!