Thank you everyone for your comments on this IEM. I finally decided to open the box and give the Primo 8s a try. Overall, I was quite underwhelmed - I guess I just expected more. Just so I get it out of the way, I took most of the advice that was mentioned on this post; things like burn-in time, Westone star tips, Comply P100s, T100s. I did all my monitoring off of my Crane Song Avocet.
This is my Day 1 review. I know it's not fair to compare speakers to IEMs but I'm on a mission to find something close. I have the PMC AML2, AML1 and Barefoot Sound MicroMain27 - I've been using these for years to monitor music so I know them very well. For headphones/IEMs, I have the Fostex TH-610, Shure e5c, Westone CIEMs and a few others. I spent most of today really putting the Primo 8s through its paces.
Primo 8s versus:
My reference speakers: No chance the Primos were going to win going into this even if they were better, but they weren't. Not even close. I consider each one of these speakers a 10 out of 10 so I will base all my ratings below against my reference speakers.
Fostex TH610: Yes, I'm sure there are far better headphones but this is what I landed on for now. For $500, it's shortcomings in the midrange is forgiven for it's sweet listening prowess. When compared to the Primo 8s, there isn't much to compare. The Fostex beats the Primos in every way except for the weaker midrange in the Fostex. Fostex is a 8.5 out of 10.
Shure e5c: I've had these for years and rarely use them because they just aren't that great. I usually keep it in the cabinet unless I get a musician that wants things really loud in their ears and I want to have minimal bleed on the recording. The Shures have both positives and negatives against the Primos. The Shure e5c has better highs and midrange. It is also easier to drive which is partly important because I will be using these primarily on travel. The Primos still have better low-end, sound stage and imaging and have less distortion. They just lack some clarity due to the rolloff in the top-end. Shure is a 4.5 out of 10.
Westone CIEM: These are even older than the Shures but they are custom molded to my ears and have triple drivers. I'm not a huge fan of these but I know them so well by now that I could dare to mix an entire song on them and come pretty close. For this reason, it's very difficult for me to compare these to the Primos - my mind tricks itself to compensate when I put the CIEMs on. But here's my best attempt - the Primos have better low-end and soundstage; Westones have better imaging, high-end, midrange. Westones is a 6 out of 10.
Ultimate Ears Reference CIEMs: I recently got these but the molds were messed up and don't get a good seal and it is painful to keep in my ear for longer than a few minutes. I don't have these anymore so I'm trying to go off of what little I remember about them but the Primos probably had better sub-bass. Everything else was better on the UE. The UE is a 7.5 out of 10.
By now, you may have a better idea on my thoughts on the Nuforce Primo 8s. I know there are several folks on here that love these and trust me, there's nothing I want to do more, but they are almost maddening to listen to. I think overall, these are pretty good if it was all I had but there simply isn't anything these do really well. At this point, my biggest knock on the Primos is the high-end rolloff, muddy high-midrange, and imaging. The Primo 8s get a 5 out of 10.
I will give it another burn-in tonight and see if things change tomorrow... Please let me know if there are any other tricks that I try tomorrow. Thanks friends for allowing me to share.