The T-900 was created to destroy other machines, and is equipped with hyper-alloy armour, and is twice as fast and strong as the T-800 series. The T-950 is a more advanced variant of the T-900, with a slimmer design more in common with the T-X series, as it was likely the precursor to that machine. It is somewhat more capable in battle, and has better software than the T-900, but aside from its cosmetic difference, the T-950 isn't all that disimilar to the T-900.