I made the sauce last night. It took about 3 hours for it to reduce down to the thickness/richness needed. I just dumped all the contents of the canned tomatoes into the pot. I think that was a mistake...lots of extra water needed to be boiled off. It would probably go more quickly if you strained some of that out but it turned out really good. Its very basic but delicious. You could easily use it as a foundation for a good meat or garden sauce.
I'd probably add a little more garlic and basil to bring up to my tastes - but I like my marinara stronger than most people.