The noob use a more "workhorse" movement and some argue the case is better, but imo the H-Factory Pams have been made very well and can be worn out of the box 100%.
And as mentioned, both SS and Ti M Series are very similar and the difference will be obviously the metal, but the new 111M also has a cosmetically enhanced movement with the new platinum bridges etc and a swandagger.
But don't let this be the sole justification of one over the other. Go for what LOOKS better to you.