Gurley has been playing hurt, but even still he's been better than Ingram/Kamara together.
If you look at DVOA, the Rams have a better pass defense than the Saints by a decent margin, and the Saints have a better run defense by a large margin. So overall the Saints defense looks better, but the Rams played the run really well last week - if the Rams continue to play the pass well and play better run defense, it's not a stretch. We have the best defensive player in the NFL and talent wise we are up there with the best defenses - just haven't put it together yet.