It works much better upgraded, but I'm sure it would function OK unupped. I would recommend upping Miracles first, as I find that the 3 less quanta can save your life frequently. After that, it's your choice. I would recommend doing some towers, then dragons, then more towers, then more dragons, but it won't matter greatly.
Using QI (and assuming 5 towers = 6 pillars), it has a QI of 5.75. This seems to match my findings, and it is a nice value, as you don't necessarily want to play your miracles immediately.