Man, you guys really baby your bikes, which may not be a bad thing BTW.
When I get on it, my seat-o-pants tach tells me to shift just a few hundred past 4K. Its here where I feel the bike slowing down on pulling. That's with stock cams. These cams don't seem to pull hard much past there and I feel like I'm shifting just under peak. If you spend a few minutes looking at all the dyno sheets guys have posted around here, they pretty much confirm this. Those dyno runs tell all actually and clearly give you an idea where NOT to go. I also find when under load when I shift at about 4200K the down shift drops me right into the torque power band again near 2500k-3000k. Again perfect because I'm right where the motor can pull like gangbusters. I certainly don't want to drop below the power band when I upshift. Again, the dyno sheets confirm these motors really start pulling at around 2200K-2500K with all that glorious torque coming on full.
I come from the inline four world of old cb750s in choppers so I'm not afraid of the rpms most motors actually need to live free. I certainly am not a lugger either and have learned not to tool around at too low an rpm. For this motor that number seems to come into question just under 2500K but rears its ugly head if you drop below 2K. Not good. Again, that's where we see the torque coming on strong.
Sometime down the road I will most likely swap to the new TTS cam. That cam still produces torque at very low rpms (which is what most of us want to have and feel) while expanding the power band up to just over 5K somewhere. Seems like the ultimate street cam to me and kind of the best of both worlds. Usually you lose low end as you add to the top end. But the new TTS cam has Gobs of power down low for that off-the-line pull we all like during our stop light drags with buddies yet a little more expansion with power in each gear by giving us about 1K more rpms before needing to shift. I'm salivating just thinking about making the cam swap but will ride one whole season with the DX pipe and baffles just for good measure and not give in to my obsessive compulsive disorder to make this bike the best it can be in the very first riding season!
For gentle tooling around I seem to shift at 3K+ like most agree. Those in town traffic rides really don't offer the space you need to get on it anyways. But I do look for the opportunity whenever it presents itself. Throttle Jockey to the core!