doncuppe, your question is a very good one and you're learning, just like I did, that you have to put up a certain abrasiveness here, but the answers are usually worth it. Best to rise above and ignore it 
I think the freq to voltage converter is an interesting idea, and measuring pulses without using interrupts, even as a thought problem, is a great question, and one I've had.
What if you want to monitor pulses from several sources? With frequency to voltage, you could easily do that, but with interrupts, there could be missed pulses, right?
I hope we have more discussion of it here, thanks for starting the thread and keeping it focused!