Even taking into account the price difference of ten dollars, the red is the better deal. Both phones have the exact same features. Except the red razr comes with the stereo headset included, while the grey one does not. Also, Sprint contributes $17 from the sale of every red razr to Project Red (Aids charity/research organization).
My opinion, from the perspective of a current Sprint salesman and Sprint user, is that you should stay away from the razr, and anything motorola for that matter, because the build quality and battery life are subpar. I see these things coming back every single day and I do everything I can to get my customers into something with comparable features and better quality. Taking a look at some of the Sprint phones with comparable features as the razr, I would suggest checking out the Sanyo 8400, Samsung m500, Samsung m610, or even the LG Fusic. I currently use the Fusic and I haven't had a single complaint about this phone since I began using it in August of last year. One feature it has over all the other phones is an FM transmitter, similar to an iPod.
Myself, I would stay away from the razr. However if you are stuck on it, get the red one and you get a free headset and do a good thing at the same time.
