The TR is basically the LE but with double the wave memory. In other words, it contains the sounds of the LE plus a whole load of brand new sounds (mainly acoustic sounds).
It also uses storage similar to compact flash (i think) - the LE uses smartmedia cards (up to 128MB). The media the TR uses surpasses the smartmedia.
Apart from that, it's the same except that it's a different colour.
Between the LE and the TR, I'd go for the TR for those reasons alone.