I know not a lot of people play the offline single player career modes, specifically the one where you make your own player, but ever since EA started including training modes like PES had in their games (you know, crossing, dribbling, finishing, etc) it bothers me that they don't implement them (at least optionally) into that mode. It seems like such an obvious fit, maybe as an in between seasons session to raise some extra stats, impress a club you want to move to or something.
I've played be a pro / manager mode exclusively the past few Fifa's (well 09, 10, 12 and 13... skipped 14), I play the occasional online multiplayer game but my Fifa games are about 90% offline / single player compared to playing against someone else.
Debating whether I should make a purchase, I skipped 14 as I was over Fifa after playing 13 for a long time it got boring (played 08, 09, 10 in a row, purchased 11 but I NEVER actually played it - it's still in my sealed game pile of shame, 12 and 13 - all but '11 were purchased 2x or more (ps3, 360, pc)).
The demo is ok, but i am not sure how long the game will hold my attention... i usually play Fifa for 4-6 months before having a mini break, then play it again for a few more months (stopping about 1-2 months before the new version comes out).