Looking for feedback on whether to buy Audeze LCDX or Mr Speakers EtherC

Additionally, note that the Ether C requires up to 200 hours of burn-in to achieve its maximum sound quality -- especially in the bass.  The manufacturer has stated this on the Head-Fi site and there are numerous posts by owners attesting to this. This is because the pleats in the planar ribbon drivers need more time to flex to achieve their designed specs.

When new without break-in, the sound is constrained with light bass. Don't worry, as they burn in the sound continues to improve until the 200 hour mark or so, when the sound is superb. 

Also, strangely enough, the soundstage on the Ether C, a closed headphone, is larger than in the LCD-X, an open headphone.

I have the Audeze Sine also, and if you change from one to the other, you will hear the Audeze heavier bass v. the faster but lighter and more natural bass in the Ether C.  Some may prefer a heavy bass (esp. for rock or hip hop) - I didn't - but the Ether C also responds extremely well to EQ if you want to add some bass to it. 

Great to know. I feel funny buying something I haven't heard, but I can't find any around here in stores...and I think from what you've said and all the reviews I've read, I can't go wrong.

One more question, dne...any recommendation for an amp with those cans? I have a Foxtex h1p1 right now, portable.

I would just say that as with any TOTL headphone, the better the amp (and DAC), the better the sound.  The Ether C is reasonably efficient -- even an iPhone drives it using max volume, and a good portable amp can do a very good job. Do mean the Fostex HPP1? If so, I had one and it is a very good portable DAC and amp -- should be fine with the Ether C. For a portable DAC/amp I'm using a Chord Mojo and the sound with the Ether C is amazing, with enough power to play so loud you would damage your brain let alone your ears.