@comradestryker
First of all, its 1200 mass per point defended (UEF t2 shield) as novax kill anything under a single t2 shield. It also required buildpower being avalable at every one of these points on the map, this takes time and increases cost.
You should have a look at how the novax was used in that replay. No other unit in the game can replace the novax in that situation. A first novax on setons is always cost effective (The same can be said with nuke)
The game would not have been won without the novax. T3 arty is almost always worse, not better than novax on setons. The novax were more effective than the mavor at less cost. and had greater impact on game outcome.
Comparing the two once a single shield is up against a shielded base is stupid, they are for differrent things, and the novax is too good in its niche . T3 arty does not kill expanding engineers or moving cruisers. T3 arty does not snipe thigs like stealthed pgens built across the map. T3 arty does not provide omni vision and scouting. T3 arty does not have infintite range. T3 arty is more eggs in one basket making it easier to snipe. T3 arty takes longer to payoff and longer to build, making it easier to scout and counter. T3 arty cannot be split against multiple targets around the map. It is not cost effective to fire t3 arty at single mexes, but it is with novax.