Well... An iBasso PB2 + DB2 on the way for the interim until the HIFI-M8's ship. The Pico Slim is up for sale - a 2 day fire sale at the moment:
The IBasso pair is probably overkill, but I've been curious for a long time about them.
Pico Slim has been exquisite with the iem's, but for some reason, I am finding the iem's better with just the iPhone than I remember. I'll have to try the iPod touch 4G, and see if that was the issue...
Now to either order a bunch of cable stuff and dig out my workstation, or have someone build me a balanced cable, and modify the Mad Dogs for a balanced split or single entry set up. I really prefer single entry - much easier cable management at work. I'll try out the iBasso gear SE in the mean time.
I don't think I'll bother with balanced for my iems.