Note: Everything that I say will be based on the default modpacks.
I quite like both Tekkit and FTB. While I agree that the Technic Launcher is far superior to that of FTB, I think that the amount of magic mods FTB has sort of balances it out. I absolutely love Thaumcraft and Mystcraft. Also Forestry. And am I the only one who loves Gregtech? It inspires new players to use machines they never did before. Before, most new players went straight for the Macerator, without even considering the Pulverizer or Rock Crusher. I mean, I didn't, because I find making starter IC2 power annoying, but you get the gist. However, New Tekkit did the same thing by removing IC2 entirely. And yes, I know it isn't updated to 1.5 yet.