I know it's not the Dually, but its comparable. I had a single 4 bulb Squadron on my dualsport and my buddy had the Trail Tech HID. The HID was brighter, but it was more of a focused beam like a 2 foot circle and the light faded out from there. The Squadron had an even light foot print across the whole beam. The HID projected further as well. The bike started to out run the Squadron around 65mph out in the open desert.
It really comes down to what you'll be using it for and if the light meets your budget.
I've owned several different lights over the years. I've had the Hella 500s, 4000s, Baja Designs La Paz HIDs, Fuego HIDs, Squadrons, Pro Comp 130s, Rigid 12" LED, and the Kragen HIDs.
Right now for me I've been running the Kragens on everything from the daily driver to full blown baja bugs, and prerunners. They can be had for almost nothing. The plastic mount is a little scary, but I haven't had one single problem with them. I just picked up 6 of them for $60 each nib.