I personally don't find that there can be universal answers to this particular question. Each arrest is different and each has their own set of mitigating factors that will drive the decision making process as to whether transport will happen or not. I will say (for those who have not experienced the joy of the autopulse) that compressions are productive and viable whether you're sitting in their bedroom, carrying them down stairs, rolling down the street, or heck, probably even upside down.
The measure of the viability of an arrest is ETCO2 in the presence of good compressions. That is our universal answer, or universal measure of chance of ROSC, especially when you're 30 minutes into ACLS.