There is some sense in using a higher MP3 bitrate when transcoding from other lossy formats to MP3.
For example,
128 kbps WMA > decoding to wave > encoding to 128 kbps MP3 will result lower quality than the original 128 kbps WMA has. Every new encoding takes something off. It would be like the original was 80 kbps or something like that.
Using about 200 kbps (or more) would at least preserve the most of the original quality.
The best solution would be to re-rip the files directly in MP3 format in case the original CDs are available.
I now also see a "Use Fast Mode" box that has NOT been checked.
You should definately try the Fast option when using VBR. It is actually not any lower quality and it is faster.
You could also try CBR at about 192-256 kbps. CBR is a bit faster than VBR Fast.
I have sometimes used this custom setting for making fast CBR encodings:
-b 256 -q 7 --lowpass 17
(-b 256 is the bitrate. -q 7 is a faster quality setting. This lowers the quality a bit, but doesn't sound much different at a high bitrate. --lowpass 17 limits the high-frequency range to 17 kHz in case the original files have anything at that range. 17 kHz is good enough for a portable and the transcoded files will be higher quality at frequencies below 17 kHz.)