The only Banks product I have is the iDash data monster and it is on my ECODiesel, I was interested in learning more about the regen process.
I've seen all the marketing hype on Banks and other manufacturers' performance-enhancing products that certainly wets the appitite. The only Banks product I would consider is their grid heater replacement but it is over $1,000. As long as my grid heater "jiggle" test passes, I'll leave the engine stock.
The engine is an air pump and the intake and exhaust are designed to support the CFMs the engine passes. Any gains made by adding expensive but pretty bolt-on parts will be unnoticeable from the facet of performance but succeed as eye candy.
The Derringer product Bank's offers sounds like it can cause the Cummins to launch to the moon but I've read very little about real-world results on the Cummins forum. There isn't much a product like the Derringer can do outside of tricking the engine controller with modified sensor readings to force additional fueling and damage your cash flow.
I'm stock, standard output, and able to easily tow everything I connect to the truck, all typically under 17K of tow weight. I also have zero issues and so far 100% reliability with nothing more than scheduled maintenance.
This is all subjective but I'll stay with my tried and true philosophy of "don't fix what isn't broke".