Answer to replies and reponses to those others that have done the route:

Me = consultant scum - ideally out Mon return Th.
Coach on a NW DC-95 wasn't bad at least for a 1 - 1.5 hr flight.
I'm like at 80k on UA (with sloppy seconds) so I'll get 1K again. Those ORD - east coast flights are too short to make lots of mileage. If I was only there again and flying out of IAD (which sucks but with the promos woohoo).
I have not yet flow the NW ARJ. I have flown their A320.
All the flights between ORD (mainline or not) and MEM are freaking full. At least during the times that I fly.
DL and UA have stopped their mileage agreement, plus ORD - ATL - MEM seem like a lot of pain.

An all UAX trip is sets me back 580USD.
As noted above, I can't do an RJ on the Monday outbound (American Eagle or UAX). IMHO RJ's just are not reliable enough for the business traveler through ORD during the summer.

Misc. Opinions

I can't get any work done on an RJ.
The American Eagle Embraers felt like better seating than the UAX CRJ, but the standing height seemed to be lower.
In May, it was a NW A320. My palm OS still shows that...perhaps NW is not updating it? I do see ARJ now on NWA.com.

and...OT really another thread but so what.

Do NW and UA use different engines for their Airbii? The NW one seemed so much stronger than the UA one. Oh and the seating wasn't that bad, but I noticed that the NW tray did not have that sliding function that the UA one does have which is really nice when working on the laptop.