Having scanned through the rules, it strikes me that this has elements from LnL, CoH, CC and BoB.
They all have elements of each other.
I find OST the easiest to play. More stream lined rules, less chrome. The impulse point system makes for some battlefield uncertainty which I like but some people not so much. Sometime you just don't get enough impulses in a turn to do what you want or need.
The unit pieces are large and easy to read, great for old guys like us. And I love the huge maps, while other complain they are too big for small scenarios.
I have them all except Pacific... neve was interested in that front much... except for naval/carrier battles.