Okay are those the crafted Invention enhancements you can buy at auction?
I generally switch to those at level 22 (start with 25) and then upgrade them along the way.
So those are still considered IOs, just non-set IOs? Got it.
And SO is just the stuff you buy out at the store/vendor, right? I've gotten away from them because constantly upgrading those gets expensive, and I'm an alt-o-holic lol.