I won't be running T5.
I vehemently dislike the task system, I can't make much headway with ACS, don't like the hundred-ton-only hulls, and don't much like the weapon design system.
Too much complexity in places it really doesn't belong, too, like alien races.
insufficient realism in others, like guns.
It has some useful tables for other editions (10diam, 100diam, 1000diam limits).
I don't regret the $35 spent on it, as I've gotten plenty of enjoyment from reading it, but I find it unusably overtaken with needless complexity and poor design choices.