I prefer the scope or optic to be over the cylinder. It helps maintain the balance of the gun better.

I tried an UltraDot in the "over the barrel" position offered by the stock rings on my SBH Bisley Hunter. I didn't like the balance shift. The Weigand mount allows the dot to be mounted further back and I like the way the gun balances better. Would still prefer it to be farther back, but I don't want to D&T the top strap to make that happen.