[1.2.2] Ground Construction v [1.2.2]Extraplanetary Launchpads

[Noel32]

Which should I use and why?

[DStaal]

Both. 

 

Ground Construction models a bit more near-term options for construction: You have to ship a portion of whatever you're building from Kerbin, although you can refine some of the materials in-place.  Basically, any parts beyond 'a bar/sheet of metal' get shipped up in a kit.  Also, you can only build while landed.  (It models your Kerbals going out and assembling the kit they've been sent.). Think of it as IKEA for spaceflight: You get the flat-pack box from the store, then assemble in-place. 

Extraplanetary Launchpads is a bit more far-future: It models you being able to set up an entire production chain off-world, so you don't have to send anything from home, although you can.  You can build on planets or in-space, wherever you want, as long as you get the materials to your launchpad - and again, those materials don't have to come from Kerbin.

 

To me, starting with Ground Construction and building up the capability to do EL makes sense.  (Though it should be a longer process between the two than it is at the moment.). Both have strengths and weaknesses, and they compliment each other well.

One thing to note: Ground Construction is in the process of being integrated to work with MKS - as a part of that, it's building resource is going to change in the next release.