Unless you're a weight freak-no. Pose value aside of course. I got the Ti one, its an excellent saddle-v comfy. The cromo one is, I'm told, the same. If thats so save your cash.
I have one of each - be hard pressed to tell the difference. I guess the Ti rails should absorb more vibration, and it comes with the swanky leather cover (or a suede one p'raps), but as I say - hard to tell the difference.
I know its often said that ti rails are better at absorbing impacts - I'm a bit sceptical about that myself. However, I do have a ti railed Rocket and its a lovely saddle.