Do you mean it has a hardware bypass for the input, like my Pro Tools MBox? This can help eliminate latency, but it means your listening to what's going in, not what's going to disc. Also, if you want to add software reverb to the cue mix during recording, you can't use the bypass. Does the lex have its own effects?
If the lex really doesn't suffer from latency then it is truly a technological marvel.
Orc