These have served me really well over the last year I've had them. The AKGs had the bass that the other in ear systems were missing for me (weren't even transmitting as I found out later when I upgraded to Sennheiser IE8s for my earbuds). So far, they've been the closest to sounding like being plugged into our Aviom system directly that I've experienced. The Shure P4M let's you hook up to 6 extra channels (4 mono signals with gain / pan controls and one stereo aux mix without gain / pan) to your IEM. It let me have complete control over my bass and keyboard rigs in my ear. The link outputs on the back also functioned as convenient balanced outs before I got DIs for my keyboard. I've found out I'm not a mobile stage personality, so, these are a bit pointless for me to own right now. If I ever tour again, this will be on my shortlist of things to re-buy (or maybe the Lectrosonics Quadra, it's all kinds of awesome but priced somewhere between the ionosphere and exosphere).
I have the IVM4's original accessories and boxes as well (though I'm not including the slightly icky earbuds). I'm looking to get
$900 shipped and Paypal'd for the system.
Trades I'll accept:
Current Generation Mac Mini Server
Ibanez SR506 or SR1306
Unity Audio The Rock Monitors
JBL 6328 Monitors
RME Fireface UFX interface
Blue Kiwi
A Designs Pacifica
A Designs Reddi
Avalon U5
A decent Acoustic Guitar (Solid Top, preferably Larivee/ Breedlove/Babicz)
Kawai MP10