Interesting question. You can refer to some of the DAM shootouts in which they've compared the smART and Mensa DI/O's with the XA777ES. Guan and I are also going to be doing our own comparison, putting the XA777ES up against Mensa and his highly modified pencil tube dac. I especially want to do the comparison using hybrid SACDs, to see how SACD on the 777ES compares with redbook from our highly tweaked dacs.
By the way, if your Le Amps sound sterile in your system I strongly suggest that you look into providing better power to them -- get a dedicated power line for your system or get a good power filter. We've done comparisons at Guan's place with the Le Amps plugged straight into the wall, plugged into a dedicated line, and plugged into a DeZorel power filter plugged into a dedicated line. The Le Amp's performance takes a jump forward with each improvement in the power you feed them and ultimately can sound very musical, natural and emotional (and this is without any tubes upstream, and using silver interconnects and speaker cables).