My work falls way more in your category, where I could be waiting hours (or days in theory) for transport out. That said, the data I've seen for front country medicine shows two medics providing good CPR/AED/drug usage in a stable environment provides a higher save rate than one guy in the back of a bus trying to do it on his own, even though they'll get a patient to a higher level of care sooner. It seems like, especially at the P level, the level of care in the field is high enough now to make a difference the majority of the time.
I still stand by what I said earlier though, that there seems to be a need for tighter criteria about do I stay or do I load and go in the first 30 minutes, but overall with cardiac issues it seems to make sense.
That's the thing though, once the meds are given, the CPR and shocks can be done anywhere. If the ER is only a few minutes away in an urban area, you're really not losing much with a few minutes of transport time, especially with automated monitors delivering a shock, and some units that even have automated chest compression machines. May as well be getting someplace if you can, doing work that is easily done in the ambo, when initial on-scene interventions have already been given.