Well, after spending a few hours comparing different modpacks, I see different advantages and disadvantages. Correct me if I'm wrong.
If I want the most mod crowded install, the FTB Monster pack has it all. But I don't know how stable such a huge install can be.
If I want a Magic based install, the most up to date mod pack is the FTB Magic World 2. Hexxit seems outdated, although it looks like it has more stuff fit for adventuring. But Magic World with one of the included Texture Packs and Biomes O Plenty looks awesome. I don't know which one of these is the most fun.
If I want a Technic Sci Fi install, Tekkit seems the best. But I can't seem to see the big differences between it and FTB Tech World.
Direwolf's mod options don't seem very interesting to me, but I might try them to learn a part of the mods I would like to use from the other packs, while watching his videos.
And about what you said, FTB doesn't seem oudated at all, many of its modpacks are for Minecraft 1.6.4...