I have both, I loved Tapout when I got it, could not get enough of it or stop talking about it and now I love DeltaFit. I have not done enough DeltaFits to comment on the overall intensity though. Both Tapout and DeltaFit have a variety of intensity throughout.
I think DeltaFit has more variety in workouts and moves, especially with the kettlebell workouts and sweat and stretch, workout from hell, etc. And I'm guessing they will get harder as I progress through the dvds.
DeltaFit with the coupon code is a great deal. Tapout has a ridiculous shipping fee of $25, not that it stopped me or anything.
Tapout ends up costing more than twice that of DeltaFit.
I think DeltaFit will hold my attention longer, the Tapouts started feeling too similar, and I did not like some of the "strength" ones all that much so ended up rotating through about half the dvds, but I was still really happy with the system. So I think they are both great systems. But I am leaning towards DeltaFit.