Quoted:
Im looking to do a lightweight build, what do the irondots weigh? Does the mini dot make a difference from brand to brand? (I assume not).
I like the idea of the Aimpoint T1, but they are so pricey.
According to my Dymo postal scale, the Docter sight weights a tubby .8 oz without a battery, and the LaRue LT627-FF mount weighs a hefty 4.4 oz. Those combine for a massive 5.2 oz. Once you add the 2032 coin battery, you're looking at likely more than the average adult male can carry. I use a porter to carry my rifles, a Lowland Gorilla actually, and frankly, he just shrugs off the weight like it was nothing. He doesn't even blink at the three cases of beer I put in his pack either. The Gorilla's name is Dog. Get it? A Gorilla named Dog. I laugh about that every time we go on patrol.
Anyway, I bought the LaRue mount for the Burris instead of the Docter mount because it has a cut out for the on-off switch on the Burris. If the Docter dies, I would replace it with the Burris Fast Fire since I can't tell a difference between the performance of the sights (I have both). They are identical in size and will fit either mount.
For your needs, the tiny cut-out would likely reduce the mount weight by several grams. Over a thousand mile hike, that really adds up.
FYI, neither of these sights compares to the Aimpoint T-1 IMHO. I consider the Docter/Burris FF VERY close quarters sights. They do work well though.
Hope that helps!