No need to hit the magic button there fella ....I have already had a 600 with full exhaust (arrow), commander and map as well as a 600 with slip on, commander, and map. Both dynoed. Evidently, it comes down to what you determine asa "big" gain.The performance gains between the two that Ihave actually experienced are negligable and not worth the cost in my opinion. Extra cc's is the way toget more bang for your buck.

 

buying a full system IMO is better for weight reduction (if you get a titanium system). you can shave a good bit of weight with just the headers alone if your stock ones are steel. You can use that at any speed but not necessarily a few hp you get up in the top. But yea, you'll need a power commander with a map to get the most out of your expenses.