I think that some people who play both FM and GT with a controller don't realise just how much assistance is given to them by the game. It makes you feel like a driving God at times but stick a wheel in their hands and they would quickly realise just how much their hands are being held with a pad. It's completely understandable because the vast majority of people play with a pad and the devs want people to enjoy the game and the only way for the majority to do that is if they get lots of assistance with the pad as it's not exactly a suited control method for a racing game.
Like others I would implore everyone to get a wheel if they can, I fully understand that is just not possible for some. If you do you will experience the game and physics as well as you possibly can and, given time, I would say everyone will get more enjoyment out of their racing games.
As for the DLC, I'll be buying all of it, it's well priced and more often than not very good.