Both can do well but you're likely to take different units in each. I run with an all transport army and it works very well for me. One thing to take note of though is the "rushing to objectives". Generally you might not want to do this, our greatest advantage is our speed, allowing us to redeploy quickly. If you go with a WWP army then yes you are more likely to park on the objectives with something. However, if using Raiders/Venoms I would encourage you to use that speed for the whole game and then zoom around picking up objectives towards the end of the game, if you haven't killed everything already that is.