Chemist of Hyrule

Does anyone on this forum have any personal experience with the NSF-GRFP fellowship. I recently was awarded one and I have a few questions. Like... Can this money ever stack with the stipend you receive from Graduate School? (I really hope so...) How does the GROW Program work? I'm currently in France and want to form a collaboration with my PI here, but I can't find any info on it really. Are there any things that I should be aware of? Things like special benefits or tedious requirements/ I'm about to enter my first year of Graduate school. (Still don't know where, between Vandy MIT and Caltech, so if you have relevant info on that I would appreciate that as well).

Have you found out more about Vanderbilt. I'm deciding between them and MIT but I couldn't visit Vanderbilt. What do you like about it?