Interesting point about component libraries. The ones provided with the early versions of DS work well enough, but some of them are wrong. I've tried creating a few myself, it's great because you get exactly what you want, on the other hand it can be hard to set up correct dimensions.
What I've found with SamacSys is that you get really good footprints, in formats for the major layout programs. If they don't have it you can create it using the footprint engine on their website, it will eventually get checked and tweaked by them. The only fault is you get a box as the schematic symbol for most component types, so you have to associate it with the correct symbol yourself.
Interesting that DigiKey are promoting KiCad (I had to check out the footprints!) I thought KiCad was a wrapper for the gEDA suite, but apparently not.
I am reminded that "pcb" is an excellent layout program. You do have to import a netlist, though is now handled by the wrapper I thought was kicad....