Honestly, I'm a big fan of TFC. It's challenging, but it keeps verisimilitude. It doesn't play well with most other mods (I saw REI's and NEI in Florastar's video), but that's because of the massive numbers of base-class edits, not because the mod developer got in a huff like a certain other one did...
Having said that, there are a lot of mechanical changes. The knapping system for stone tools would be a prime example, someone new to TFC would not necessarily find it intuitive. So it pretty much requires having the TFC wiki up in the background and referring to it constantly. Nothing wrong with that, of course, and once you get the hang of it you won't be flipping over every other second. But starting off... yea, it requires some documentation support. So I would not suggest this to be a mod to go into 'blind'.
I would suggest it to anyone who is wanting a change of pace. It really does have a different mindset to gameplay. You can't really 'rush' through the beginning phases unless you get insanely lucky with spawn. The 'tech tree' flows rather smoothly, and progresses at a decent rate, subject to materials available. And just wait until you get to actual smithing... the player's skill at the smithing mini-game has a mechanical impact on the item's durability. No automated crafting here.
In fact, there's almost no automation anywhere, which is going to be a real departure for most FTB users.