5 Port setup will make more power....but it usually makes it at a higher rpm and they are a bit harder to tune.
Another thing is that not all events allow 5-port. I know roar rules specify 3-port for racing , but it usually just depends on where your racing.
3 Port will generally make good power down low as well.
Also the need for power depends again on where your racing. Is the track large is the competition really fast are they running motors like this.
You really only want to be as fast as the first place guy if not a little faster than that....but not much more. Too much power just gets harder to handle , puts more wear on the tire and could essentially cause more fuel consumption causing more pit stops.
So I would base your decision off that. If you have a huge track where speed and power counts. Then 5 port rody would be nice im sure. If you want more low-end and its not a big track then the nova would be fine.