[andoman]

I now have a couple more rides on the Arrow. I stand by my first assessment: Better mid-range than stock.
Since the Arrow was such a dramatic change in pipe shape, I was worried that it was going to change the power-band dramatically as well. This is not the case. Same smooth, linear, rideable power-band that I've always enjoyed.

First, I have to describe my normal type of riding as well as my style.
Type: Fast flowing single track trail. Some technical sections, an occasional long gnarly technical hill, long rocky sections with loose softball size to soccer ball size rocks. In these rocks, there is no rock avoidance. They are rock on rock, so only the big ones can be avoided.
Riding Style: Rekluse and LHRB. I go fast by spending most of my time in the mid-range of 3rd and 4th gear. I keep my momentum up and avoid the cut and thrust of braking and gassing. I try to ride smoooooth.
Throttle control is my mantra.
Zen is my right wrist at one with each knob of my rear tire...

Specific description of the Arrow's "better" mid-range: I find I shift less. Simple as that. I can be just a tad too low on the RPM and not need to shift down where I would have had too with the stock pipe. It's not that I'm riding a gear taller everywhere; I'm riding a gear taller more often.
Due to my Rekluse and LHRB, I don't have a clutch lever to fan when I'm slightly down from optimum on the RPM. So if the throttle won't bring it back quick enough for me, I have to shift down to rev her. Then I quickly shift up to drop back into the middle of the power-band. With the Arrow, throttle will get it back into the meat of the power band at times that I would have had to down shift.
Put another way, the torque curve feels like it starts climbing a little earlier than with the stock pipe. IE.: The mid-range has been broadened to the left.