As for "levels" of the old WCs, MEM is the enhanced version. The "basic" version was more like a Greyhound Terminal (ie: LAX, HNL). The MEM club is like all the DTW clubs as far as decor/ambiance.

As for amenities, IMHO the "enhanced SC amenities" you mention is a downgrade from the "basic" WC offerings.

As far as domestic airline lounges go, I think MEM SC is a nice one. As others have said, it tends to get crowded.

It's not located in the "mainstream" of the DL terminal. It's close to security, in the main "hallway" that connects the various concourses. If you're connecting mainline DL to mainline DL then it will probably be a walk towards the security checkpoints (but not thru them) then a walk back into the main concourse.

Steve