I've worked probably 20-25 codes in my rather short career.
1.) Do you transport cardiac arrests?
Except for valid DNR or obvious death, yes, unless they meet certain criteria for field termination (20 minutes of asystole, exhausted all efforts, family agrees to terminate, and so on. If the family wants them transported, we usually transport. If there is suspected need for autopsy, we tend to transport. It pretty much all depends, but short answer is yes.
2.) Do you WANT to transport cardiac arrests?
I've had one (that I can remember) where ROSC was obtained at the hospital and not in the field - and that was from one more round of epi so it was probably inevitable had our transport been longer. I don't mind transporting them. I figure I'm not going to drive crazy fast or out-of-control, in fact when I drive a cardiac arrest I tend to go the speed limit or 5 under if we're close and extra smooth. There isn't much the hospital can do that we can't.
3.) What are the benefits gained?
CYA. Gets us out of a busy/unstable scene in the cases of drownings or assaults or trauma codes.
4.) What are the risks?
More people in the back, standard emergency transport risks.
5.) Should any code blues be transported or should they all be called in the field if no return of spontaneous circulation?
Absolutely. Not all of them should. Some definitely should. I think as autopulses and portable vents become more common, this will become less of an issue.