While I do not use a spotting scope, I absolutely agree with this opinion. A spotting scope will allow you to change the point at which you are seeing/focused on the mirage and may well assist the shooter. You can also adjust the scope to get this same focus, but I find that tedious as well. I tend to use a combination of mirage through the scope and position of the flags to read the condition. In my opinion, like most things in this sport, there is no one answer other than the one that works for you.There is a caveat to that idea: the mirage you see in the rifle scope resides only in perhaps the last 30 to 50 yd of the bullet trajectory before it impacts the target, because the rifle scope will be focused on the target face. As such, its use as a tool for estimating the effect of wind on the bullet's trajectory is limited because the bullet has almost reached the target. Although you can certainly use such mirage in the rifle scope to help estimate the effect of any wind, it is far from the whole story. A spotting scope will allow you to observe mirage anywhere in the bullet trajectory. Many shooters find it useful to focus their spotting scope on mirage somewhere near the middle of the trajectory.