If i recall correctly CDEX uses the Lame DLL, while still quite good it does not offer the same number of options as the Lame EXE.
willebear, ripping and encoding MP3s is a time consuming process, irrevelent as to how fast your CD rips and your CPU encodes. So take the time now to figure out what ripper and what encoder (and settings) suit you best, and don't forget about the ID tags - idealy your encoder should do them for you. Oh and also check what file naming convention suits.

A good read is the r3mix site.

Finally the personal bit - I am using AudioGrabber, but also recommend the freeware EAC. Enoding with the currect release of Lame.exe using the "--alt-preset standard" preset.