Received my Rotary which I ordered about a year ago to replace a defective 170T. In comparison I'd say I like the beam pattern of the Rotary but preferred the more neutral tint of the GDP 170T. The bezel of the Rotary is aligned with the body of the light better, the 170T was slightly misaligned although it had no effect on the light. The Rotary bezel is also thicker, I have a SF diffuser cap that fit very loosely onto the 170T but is very snug on the Rotary. I also prefer the flush tail cap of the Rotary to the raised of the 170T, having the ability to tail stand, albeit wobbly, is a plus too. I'm thinking the flush tail cap will be more robust as well, the raised button on my 170T tore along the side and started to resemble a broken eraser on a pencil, probably from the stress put on the sides when depressing the button from different angles. The little screw on the tail cap of the Rotary doesn't bother me, although I thought it would, but the lack of a pocket clip, at the least to act as an anti roll device does. Overall I like it however the long wait and the fact that it's a warranty replacement made receiving it a little less cool then the first time. Quick runtime tests with RCR123s (AW) gave 0:31 on max (burst disabled) and 1:09 on high, primaries are next and results should be better. The only issue I had was when I ran the RCR123 down to the lowest level and the light started blinking I did a battery change to a fresh CR123 yet the light continued to blink on low and not recognize the new battery. Opening and closing the light fixed it but I was surprised it didn't instantly sense the voltage change, I'll have to watch that.