My personal opinion is that the A-D and D-A of the E-mu cards doesn't really have any components that fall short. I'm not sure where Teacher decided that that was the case. Nothing against him...it's just that in my own usage I've seen no problems and the only major criticism I've seen is the level of the coax S/PDIF voltage...
The M cards have their analog ins and outs at a dynamic range A-weighted of 120.
The Layla 3G is at 113 and 114...still good, but more along the lines of the non-M.
And honestly Minofifa, do you really need me to give you a comparison? I suppose I'll do it anyways...
No 192 kHz for the Echo cards. Strange that even though it can do 96 kHz, the analog section is only rated from 10Hz to 20kHz (rather than 40 kHz, the typical measurement for 96kHz capable gear.) It's probably perfectly fine up there...we'll chalk it up to marketing copy oversight... Phantom power on the box (like the E-mu, as opposed to software switched on the Gina). Mic pres an unknown quantity, though if they're anything like the Mona pres they should be good (Mona pres were comparable to the Aardvark, IMO, and I tend to regard both as being slightly inferior to the E-mu pres.) Only 1 MIDI IO for the Layla. Whole rack space rather than half-rack for the E-mu. Unsure of support for S/MUX on the ADAT.
Likely better drivers. The key elements here are going to be WDM support, GSIF (though that's slightly less important since
Gigastudio 3 will support ReWire), and multi-card. Not sure of the universal inputs have the proper impedance to work as guitar DI. (The E-mu doesn't.)
If this was at market at the exact same price as the E-mu and I knew for certain that it would properly support WDM and multi-card usage in drivers...no question. I'd get the Echo Lalyla. Even though my current software platform of choice, Sonar 3, supports ASIO, it supports multiple card drivers via WDM, and right now I seriously need more inputs than the 18 I have courtesy of E-mu.
If you can wait until Echo comes out with these cards, do so. If E-mu doesn't properly support WDM and multi-card usage with its drivers by then, there's absolutely no reason for it to keep you from choosing either of the Echo cards. If I find out that the pres on the Echo are sensational, then I might have to get a Layla.
BTW, Consumer and professional changes the levels...profsesional gear works at a different line level than consumer. You might know this as -10 and +4. Any sound card worth its salt has this.