My husband and I both run in the Speedcross 4 for our daily 4-6 mile long trail runs. I was a little nervous spending this much on a kid's shoe, but my son is slipping and sliding and falling as he is just starting to get into trail running with us.  Obviously we can't have him getting injured, so I bought these for him.  They are very much on par with the grownup version.  Not cheaper, just as good.  I am very pleased with the quality and construction.
 He is growing, and some other shoes that we just bought are size 1 and seem to have more room.  These seemed a bit on the small side but still useable.  I'd say go up one size.  I would return and order size 2, but they will be useful for my younger daughter when he outgrows them very shortly.