Last month I had Honda instal the Cobra PowrPro Fi2000r, Air Intake and Speedster Swept exhaust system. I can write now my (non-technical) findings, after fitment, adjustment, and riding.
When Honda (Australia) fitted all the above, the standard exhaust had Oxygen sensors, the new exghaust system did'nt have them, so Honda left them unplugged - but I have no adverse reaction to this, eg: Engine warning light continuously on etc etc as I have read in the forums - so no need for the 330ohm resistor.
The only adverse reaction I did have was the "popping" or backfire on deceleration - which actually made the exhaust quite loud - even if you tried to ride slowly to keep noise down, as soon as you were off the throttle, the popping and backfire would make the exhaust loud.
So I then rode the motorcycle from Melbourne to Adelaide, roughly 800km's.
So anecdotally, the bike sounded much, much better - throttle response is immediate with no lull or flat spots, and power/torque was available right through the whole rev range in each gear. The bike seemed to be more powerfull, but then I appreciated that the sound alone could give this impression, without any power improvement at all.
So in Adelaide I visited a performance bike workshop, in an attempt to get the pair valve blocking plates installed. The mechanic said this was overkill, so he pulled off my air intake cover, pulled the rubber hosing out and blocked it with a plastic knob jammed into the hose - so air supply was blocked negating any need to instal pair valve blocking plates, so that should the bike be pulled over for inspection, it was a simple matter to make it compliant again. He said he's done this to many different bikes.
The result was no backfire at all now. Completely gone.
So then I explained to him about the Cobra PowrPro Fi2000r. He basically said impossible, it cannot read anything as the O2 sensors were redundant now with the new exhaust. Although after a quick check on the internet, he did believe me. So we put the bike on the DynoTune to see if and what the PowrPro did.
I have the Dyno chart, but in summary it appears around a 10% improvement in both horsepower and torque - I am getting 60.48hp at 4500rpm and 77.59 Torque at 3500rpm. he was actually quite impressed the PowrPro does at it states it should do, and in fact the engine runs slightly rich, which he said was better than running lean.
Bottom line - the bike sounds awesome, 100% improvement, the response at throttle is immediate and smooth, and definitely feels like it has more power. The bike looks much more pleasing aesthetically with the exhaust and air intake. If required I can add the Dyno graph as an image file.
For the $1500 odd I've spent, I'd say the improvements were well worth the expense. Highly recommended.