I have a DI2 SW Roubaix and the IF Ti bike. If my wife bought me the Roubaix I would damn sure ride it. lol I like my Ti bike, but it's going on ebay soon. Why? It's heavier, not quite as stiff, though it has a smoother ride. But then my Parlee is smoother than the IF and lighter than all of them. Ti is pretty indestructible but I try not to crash so I don't consider that an issue.
I would say as an all around bike the Ti bike is fine though I seem to have moved on to my CF bikes as my preferred rides.