I have found that with my current, modestly priced rod and decent line about 80' is my maximum with consistency (including leader, so 80' from me). This is with a 6wt and a WF line. With a better rod, perhaps a line size or two up, and using a shooting basket I suspect that could be extended a bit.
The main fishery that I access where this could sometimes be helpful is casting off the beach for salmon.
That being said, watching someone who is really good is inspiring!
