I sell all 3 of your choices. My 0rder of recommendation would be:
1) Fantom XA
2) Triton LE
3) Motif

The Triton Le is the least expensive with the Motif and then the Fantom close behind.

Now, if you were considering the Motif ES, this would be my first choice. What you get in the ES is much better acoustic samples, phrase factory and improved everything else.
However, for the money, the Fantom XA is a powerhouse. It is very good with sounds, sequencer, sampling and have pads for programming drum beats and storing loops. It does not have exactly the same sounds as the more expensive Fantom X and does not have aftertouch, but both this and the Triton LE I think you will find easier to use over the older motif.
George Kaye
Kaye's Music Scene
Reseda, California