Xeno Bank Construction - Bad on its own

It replaces:
-Trade Center that gives +20% economic boost and cost 90 hammers
-with Banking Center that gives 24% economic boost and cost 250 hammers

Not very cost effective. Still, if you do research Xeno Bank Construction, research Galactic Stock Exchanges as soon as possible, since:
-Stock Market gives 30% economic boost, 10% morale boost and costs just 150 hammers

Yes, it's cheaper then Banks.

Manufacturing Centers - Bad, but useful for starbases

It replaces:
-Enhanced Factory that gives 14 industry points and cost 100 hammers
-with Manufacturing Center that gives 16 industry points and cost 200 hammers

Twice the cost for very small gain. Still, tech also unlocks one economy and two mining modules, so it could be useful if you focus on starbases, especially resource mining.

Industrial Sector - Very bad

It replaces:
-Manufacturing Center that gives 16 industry points and cost 200 hammers
-with Industrial Sector that gives 20 industry points and cost 400 hammers

Very ineffective. And makes developing of new worlds very painful.

Xeno Entertainment - Only bad if taken too early

It replaces:
-Entertainment Network that gives 25 morale bonus and cost 55 hammers
-with Multimedia Center that gives 30 morale bonus and cost 100 hammers

Twice the cost, small bonus. Still, Xeno Entertainment on its own gives 10 moral bonus, and cost of 100 hammers is not much, so you do want to research this, but only after you build Entertainment Networks where you planned.

Extreme Entertainment - Bad early, useful later

It replaces:
-Multimedia Center that gives 30 morale bonus and cost 100 hammers
-with Extreme Stadium that gives 45 morale bonus and cost 250 hammers

Now it does make things +50% more effective, but in early game 250 hammers is really prohibitive. Also, tech gives access to Ultra Spices that give +15% moral boost. So you do want to research this, but only after your worlds get a bit advanced.

Zero G Sports Arena - Bad, exempt for Gravity Accelerators

It replaces:
-Extreme Stadium that gives 45 morale bonus and cost 250 hammers
-with Zero G Sports Arena that gives 50 morale bonus and cost 300 hammers

Not worth the effort. Still, tech gives Gravity Accelerators that increase ship speed, so research it only if you want that benefit.

Virtual Reality Center - Very bad

It replaces:
-Zero G Sports Arena that gives 50 morale bonus and cost 300 hammers
-with Virtual Reality Center that gives 60 morale bonus and cost 400 hammers

400 hammers! There is no chance to build something like this on new worlds.
On the plus side, this tech does give access to Virtual Reality Modules that increase moral planet wide, but it hardly offsets its problems.


P.S.
I added this article to GalCiv wikipedia:
Link