There is not a valid reason not to buy the Roubaix if this is the bike that is desired. My Roubaix was included in the recall. My collar was replaced and from what the owner of the shop and myself could see, there was no corrosion to the collar. I do not ride mine on a trainer either. The "so called" corrosion problem was from sweat while riding on a trainer. This was told to me by my trusted bike shop owner. He had read this direct from Specialized.
If my future shock becomes outdated,then I would bet I could find a spring with the proper rates for a replacement. It is a spring. Not a proprietary special gear or other some such device.
It appears to me the naysayers of the future shock are just jealous they do not have such a comfortable riding bike. Get off the fence and buy yourselves a Specialized with the future shock. You just might find you won't go back to your old bike.
Everyone has their own opinions on the different aspects of bicycles. Trying to dissuade someone from buying technology makes no sense to me. Suggest they ride the bike in question and make their own mind up. After all, they are the ones with their butt on the seat.