Flux Regulation is alright. Generically, I think Electronic Warfare is better. If you have phase ships, Phase Coil Tuning is better. If you're going for Cybernetic Augmentation, Neural Link is better. Basically, Flux Regulation is a lowest priority skill, but it isn't pointless like PCT with no phase or NL with no combat skills.
Best of the Best feels similarly alright, except it doesn't have competition as good as FR. Support Doctrine is a skill. But if you aren't looking specifically for a SD build, you will pick BotB. But you have to pick 4 other skills to get BotB first and you probably will, since Leadership is a pretty good tree. If you want to buff fighters, fighter skills are here. That aside, Crew Training is a good generic skill, Tactical Drills is okay, Coordinated Manoeuvres is deceptively good, Wolfpack Tactics is good early game and I suppose it exists later on. Then we have the good stuff, Officer Training (or Officer Management if you're going wide). You're going to arrive at BotB simply by going on the path of the most convenience.
For sheer power... It's better than the alternatives. There's typically no point to going all in on combat and likewise goes for Technology (unless you're going for a killer Radiant, which is excellent), leaving you either to go all in on Leadership, do some SD-DO spam or spread the points mostly evenly. You'll either forgo Combat for armchair admiral playstyle or forgo Industry for a balanced playstyle. BotB simply offers a good power/convenience ratio.