I use Earsonics SM64 IEMs & Beyer T70 (250 ohm). Right now I'm using a 4G Arrow that I finally received just yesterday, but I plan to order a ALO Rx Mk3-B because I'll likely get another set of (harder to drive) fullsize cans over the next few months. Plus any portable amp that I get can also be used in my transportable setup (rMBP + Meridian Explorer) when I travel (& stay in hotels) for business. At least those are the rationales for my spending splurge! =p
I am actually using it with Arrow 4G and I like it alot. Ofcourse adding an amp to what is advertised a portable DAP defeats the purpose but that is the only solution. I was thinking of getting something like P-51 mustang should match them fine.
I was told that ALO international pairs nice with it but I dont plan on using its DAC and I dont need the balanced connection so dont like paying for something I dont use.
I just wait for now and see what the future brings for me.