[average_joe]

I am not 100% done with my review, which will be here, but here is my write-up so far:
 
 

Sound signature: More laid back than the iPhone 4S headphone out with a more spacious presentation that retains the 3D qualities of the iPhone.

Sound quality: Depending on the headphone used, the technical improvements vs. the iPhone 4S range from small to significant. The 4S sounds good as is for what it is, but lacks resolution and doesn’t have great control in the bass region which results in the good but not great sound. The i.Fuzen has quite a bit more control than the iPhone 4S which leads to more clarity, transparency, and instrument separation, but it depends on how controlled the drivers are to start as BA drivers tend to be easier to control.  While the i.Fuzen has a higher resolution with the 4S, the difference isn’t all that large and the differences are in larger part a result of the amp control than resolution and the difference in presentation makes an equally large difference to the sound, opening up the sound more.  I don't currently own any amps that have all that close of a price point, but I was pleasantly surprised by the i.Fuzen given the price and my previous experience with similarly priced amps.

 

 

[phntmsmshr]

Sounds promising but might hold off until we see what iPhone Apple may or may not release in 2012, if they hold true to form then iPhone 5 would be a mid-year release and would hate to buy the iFuzen only for the new phone to not fit in it. 

 

[average_joe]

My review has been completed here, the last review in the first post.
 
And sure, it may be worth finding out more, but if you have a 2 year contract with your 4/4S you may have more time than you think with the i.Fuzen

 

[squintypanda]

Posted this in another thread just now, but I think it's worth posting here again to "warn" some about the iFuzen unit.
 
"I just bought this unit a couple days ago and while I'm satisfied with it's overall construction and sound quality, I do have one HUGE gripe about the unit.  
 
I'm currently using it with my iPhone 4S and Shure SE535 IEM.  When I'm on the go listening to music and want to make/receive calls or use siri, the sound will come from the iPhone unit itself and not through the headphones, thus I'd have to take off my earphones and hold the phone up to my ear to be able to hear anything.  I'm sure anyone could imagine how inconvenient this would be.  Not sure if Auzentech can come up with a firmware update to fix this problem so that ALL sounds would come through the amp as it should be.  If they can fix this problem I'd say the product is worth a look, if not then I'd return the product if I could... =("