What are your planned uses for it? That will help determine which one to get. I sold my Rift to get a Contego, as I love CPM-M4, and I want the bigger blade for camping when I can't take my fixed blade (Boy Scout campouts). The 940 is better for a sheeple-ridden area, as the green handle and smaller blade is less "intimidating." I will be getting another Rift, and my son fell in love with the Rift as well (it's his Boy Scout knife).
The 940 can be had in s30v, D2 (if you can find one), or CPM-M4 -- if you're willing to pay the price for it. The Contego is in CPM-M4, and the Rift can be found in a LE model with CPM-M4 or the standard 154CM, which is not a steel to sneeze at since Benchmade does an awesome job with it. I wish they would come out with the Rift in M390, but the 154CM holds its own quite well.