The advantage of a modpack like feed the beast FTB is they take care of all the incompatibilities and making sure Tinkers Construct Bronze is ore-dictionaried to be the same as forestry bronze same as all the other bronzes. Also tweaks to ore generation are important. Finally one important feature modpacks do is make the style uniform. It would be weird to have a 99% technology based modpack with 1% being terra firma craft. Or imagine a 99% magic themed pack full of witchery and thaumcraft and blood magic (not really my thing) but 1% AE2.

The role of a modpack group like FTB is almost perfectly analogous to linux distro. You could figure out all the dependencies by hand and namespace everything, but the Debian guys did all the sweating for you, so may as well use their metadata.

A long time when I was starting out I was a little overwhelmed by the modpacks having a hundred mods. So I'd start up with exactly one mod installed, lets say IC (the original) or just railcraft or whatever. But that leads to heartache and wasted effort (what, I need BC pipes to hook a railcraft boiler to a turbine?).

What seems to help is hard core quest mode packs. Crash Landing might scare people away, its kind of intense (but intense in a cool way). Agrarian Skies? Some HQM packs are so confusing they almost require watching youtube videos to figure out how to get past the first steps. Maybe FTB infinity evolved in NON-EXPERT mode?