Which Contabands are you looking at? The Nitrane Contraband is very similar to the Delta, with the same ankle strap and highback. From what I know, they're incredibly similar (other than the Contraband strap). Between the two you'd just need to decide if you want to spend the extra bit of cash for the Contraband setup over the Delta.
If you're thinking of just the normal Contraband, definitely go with the Delta. The new highbacks are awesome.
I'll be surprised if you dont like the contrabands. I'm rocking them on both my all mountain and park board setups and they are sweet. The quick strap in is a breeze, setup is annoying but doesn't take long. Very light weight, and if you haven't tried canted foot beds before you'll love em...well more so your knees will thank you. I've got a bum knee and since riding the 4.0 canted footbeds the knee pain has been reduced from riding. IMO the only draw back to the binding is the time it takes to setup. Enjoy riding the contrabands!
I love my '10 Contrabands with wedgie but so long as you are riding only one pair of boots and you already know your stance they are painless to set up. Having to adjust them for different riding styles or to let your buddy ride them with different boots, they are a pain in the ass since they need to be totally taken off your board to adjust.