I looked at the Ultradot as you suggested. I went to Ultradot's web sight. They look like good products. The lightest tube type is 3.9 ounces with rings added I'm guessing they would weigh about 5 ounces. I'm not sure the savings in weight from the current tube type I had would be worth the price.
They also have a screen type lighter weight red dot but it looks like the same design as the BSA so, once bitten twice shy.
I guess I'm staying with what I have.
Oh, well.