The thing I like about dbpoweramp (not saying others don't do this as well) is that you can point the file selector at some directory tree structure, pick 100 cd's worth of music that you need to transcode just by clicking checkboxes, and then set it off on it's way. It will churn away for days on end if necessary transcoding everything you selected in some other folder and maitain the whole folder structure. It will also transfer the tags as well. So if I've got a big library of tagged flacs organized with a \genre\artist\album\ type file structure, I can translate the whole thing to mp3 via LAME in some other location, the files all end up with the same \genre\artist\album\ folder structure, and the mp3's are all properly tagged. All with a few mouseclicks (and a lot of compute time....). You really can't ask for much else from a transcoder, although I'm not saying nothing else does this. Just saying dbpoweramp does it quite nicely....
Also, when converting from wav to flac you can select something like "delete original after conversion" so that as it creates flacs it deletes the wav's as it goes, so you don't run out of disk space halfway through your transcoding.