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.