Dean,
your explanation was better, tho.
Beep,
if you don't have some good analog hardware effects etc. just analog summing probably won't make too much difference. Others may disagree and find that digital mixing gets to congested (that is the word I hear bandied about). I don't find this this case (so far!), but if you give me a vintage neve or api I know the summing would be different because of all the (good) circuitry the tracks are going through. That is what digital summing tools are all about.
What is less argued about is summing w/ real analog comps/Eqs etc. If you have an extensive outboard collection it hardly makes sense to only use it during tracking. Even a few good units on the most exposed tracks help get a "pro" sound.
Finally, just mixing your stereo signal through nice analog outboard can help. That's what I do. I haven't gotten around to summing through my ancient encrusted rasma mixer. But I do send a stereo mix through some nice Komit compressor/limiters I have. I'm fixing to add the warm audio Tone Beast preamps to that set up. It adds choice of transformers, gain, output and other things into the circuit which are a lot of fun tracking w/. Since I got a second one I think it would be criminal not to try it during mixdown.
@