I normally use the Wyeast nutrient but when I run out I pickup the brewcraft nutrient since that is what my LHBS carries. I've never noticed a difference between fermentation or flavor. Lately I've been using a bag of "Fermoplus DAP Free" that I got from a wine maker friend, and the results are the same.
On my long todo list, I've been planning on doing some split trials of different nutrients to see if there is any noticeable difference. Who know if/when I'll ever get around to it.