I don't have much practical experience here but I asked tons of questions over and over and viewed a lot of dyno charts. Slipons/ full system/ stock exhaust/ duals/ single????? My main concern was exactly what you are asking about -- low end power vs peak power. This was important to me because above all else, I wanted to improve performance.
I went from stock exhaust to full system. I was tempted to go with slipons because:
1. The anecdotal low end loss with a full system.
--------There is no low end loss with my full system that has any impact on how i ride on the street. If there is any loss, it is in the first 1K rpm right off idle, while I am releasing the clutch. I can't say for certain that there even is a dip in power. I think the dif might be that i can hear the bike take off now where it was so quiet before. I do not need to ride at higher rpm to maintain streetable power at all. I can still prowl at 2K if I want.
2. Duals look very good.
--------They certainly do. The 4-2-1 has its own aesthetic also. The sprocket side of the 14 does look a bit blank now. Brocks makes a superb full system for the 14 that comes in duals.
3. Slipons are cheaper.
----Look at the prices and compare. The price of slipons is not that much less than a full system. I couldn't see spending money on slipons just to turn around and buy a full system later on.
4. full system is more work to install.
It is.....but a great way to get to know the bike better.
5. Full systems require tuning.
I guess they do but almost everyone uses at least a base map no matter whether they run slipons or a full system. It is no big deal. I had the PC on there for months and enjoyed a Stock map before I switched to the 4-2-1. I run a map for my full system and i don't feel that it requires a custom tune.
Here is the way i see the change to a good free-flowing aftermarket system: The engine may benefit from back pressure at low rpm (maybe just a little). After the motor gets turning, back pressure is in direct opposition to acceleration. I used to describe the 14 as feeling like there was some kind of mysterious, explosive power humming in there over 3K rpm. It was a little scary to feel all that power inside the bike and certainly, to see the great speed and acelleration it could produce. After going to the 4-2-1, I now know the the feeling that the engine power could fling the bike apart was the restriction of the stock system. It feels totally free to fly -- it lets all the power out and it is 2x as scary now....but good scary. My busa with the stock system feels absolutely atrocious now. It is boaring as hell.
The 4-2-1 seems to run cooler but this is not a good time of year in Northern Wisconsin to make that call. The muffler does not get nearly as hot and it cools of in 2 minutes. In addition, you can maximize the weight loss with a 4-2-1. The weight loss has such a large impact on handling that IMO, i would go full system for that reason alone.
The only downside to the full system is that it pops on decel. When I first installed, the popping happened really bad after the motor warmed up. I have reduced that ~35% with a PAIR block off and running high octane gas. The Popping is now not much issue when riding at normal street rpm. Tuning may improve it more. Incidentally, people who run slipons also mention that they get some popping. I imagine duals are better in this regard because the unspent fuel is distributed between two pipes.
One more thing, A full system has fatter pipes so your ground clearance will reduced under the bike a little bit. Just watch the wheelie descent.
I like my Cannon. Great power throughout the range, nice price. Buy yourself some earplugs though -- it is LOUD!
'08 MIDNIGHT SAPPHIRE BLUE Now Deceased