I have to admit that this thread is bothering me a little. Let's start with this observation ---- anyone who plays well enough that the four ball run out is a sure thing will also get out off the 6 - 8 combo every time. Which choice a top player makes here is virtually inconsequential, which is why I could care less how they would play this.
Jude has provided an exceptional example of how taking a dynamic view of the position can enable players of all levels to get out from here. That makes this an important thread that provides a good lesson. Pool maxims like "don't shoot a combo when you don't have to" are all well and good, but every rule has exceptions, and a nice example of a n exception has been offered here.
Would anyone tell the "C" player on their league team to go for the four ball runout? The "C" player is a heavy underdog to complete this runout, but if they simplify using the 6 - 8 combo and execute it, they're a clear favorite to run out.
I will add that I've often seen pros play combos in this type of position.
Nice thread, Jude!