I have both and enjoy both, but I like my operative more. I just can't get over all the constant stabbing and slashing of concealment. It's too fun. They were pretty squishy before 3.0, but have got some nice buff since to help with squishiness. If you aren't rooted as a concealment then you really shouldn't die with roll. I think the burst is fine, even though it would be nice to have double back stab, but I'm sure that would start a QQ train so I'm fine without it.
My suggestion: roll both and enjoy. Both have more of a hit and run burst spec (deception and concealment) and both have a more sustained dot spec that can still put out burst (hatred and lethality).