what exhaust brakes you guys prefer & why?

I went with the PacBrake on my 2006 5.9 Cummins for the reason others have, ie. air compressor and tank to use for other things, but mostly because the Jacobs uses a vacuum pump that comes with the kit and a new fan belt to run the pump. I did not want to have a vacuum pump failure as I have read that this happens and fries the fan belt, which would leave you stranded. If the PacBrake air compressor fails, no biggy, just no exhaust brake and i can keep on truckin'. I looked at both systems really hard as to how everything is hooked up and found that both system are identical with the exception of how the air is produce for the air cylinder on the exhaust brake. PacBrake uses the air compressor/tank and the Jacobs uses the vacuum pump that comes with the kit. Now I am not for certain that on your 1997 Dodge Cummins you would need to add the vacuum pump as it might already have one. You would just need the exhaust brake. I would just look into each brand and see what is needed. I hope this helps. FYI I am on my 2nd air compressor from PacBrake. The first one failed after a year because of the duty cycle being too light. Also if you already have an onboard air compressor, PacBrake just sells exhaust brake only kit that has all of the necessary components to connect to your existing system.