[LAU] About Algorithms

Hi to all, I'm an audio engineer in my day (and night) work, but definitely not a programmer. Yet there is one endless discussion between friends and colleges of mine that I usually do not participate in due to the lack of knowledge. The topic is algorithms of software (DAW) mixers. Some people say that they can hear a sound difference between several kinds of software mixers (e.g. Cubase, Protools etc.). I must say that I never made any serious A\B testing but I didn't notice that there is any difference. Although I do work with Pro-tools and Cubase (in other studios), most of the time I'm actually using Ardour (and I'm loving it). My questions would be: 1. Is it only me that can't here a difference between different DAWs mixing algorithms? 2. To the developers out there, what is your opinion? Is there a better/worse algorithm, or is the whole thing another "pay 600$ for this software - it has great algorithms!!!" hype? 3. If there is a difference what's the explanation? 4. Analog emulation plugins. How does one "emulate" analog waveforms in a digital world? That sounds like a paradox to me. Hope that's not to many questions in one mail. Thanks for your time Moshe