.....The ESW's have incredible bass and detail, and these are the Portaphiles best assets.
That, and the price is very fair.
For high-quality recharchgeables for the Portaphile Maxxed: 9V 520mAh Professional, 9 volt Lithium-Polymer, $20.95 at BatteryJunction.com. My older 500mAh Li-Po's last 8-8.5 hrs. continuous play. No comparison with my Tomahawk's 400 or so hrs. on 2xAAA, but the sound is worth it to me -- and, as monsieur Immtbiker will tell you, it's just dandy as a desktop amp tethetered to AC power (near-home amp sound in a matchbox ... or something...).
BTW -- Predator and Pico are really swell-sounding amps, and of course they've got the DACs ... but ...
Well, that's my last appearance for the next few months.