That would be me, but not for SimHQ...don't work here anymore.
in general... if you want real world WRC action then WRC5 has all the tracks, drivers, teams etc etc of 2015... but nothing else. No Rally Cross, no Hill Climb which both others have. WRC5 does have the best sound thou, based on you tube videos I've seen of real rally racing. But controls and road feel are the worst of the 3, like driving on glass.
If you love the man, Sebastien Loeb, then that's the one to get. Lets you customize everything, names, team names, numbers, car color and patterns etc etc. The only one that gives you a "home base" that lets you just go drive and practice as much as you want, great for learning how to properly use the hand brake, hard to do with the other 2 because of no practice field, just tracks.
Has a great relive Loeb's life, races... real videos of him, and you racing his races throughout his whole career. Weak on sound and graphics, and feel. except the best for a gamepad gamer so far.
And as for Dirt...well cats meow in sounds and graphics, and gameplay including online play. All 3 have online play but no one is ever playing the other 2, not to many with DIRT either, but more then the other 2. So MP goes to DIRT.
DIRT has the most content. the DLC came with the pre-order, Loeb was 60 bucks for the game and 3 DLC packs for another 25 to 30 bucks total, those DLC should of been included IMO. of course Dirt has got nice rally cross and hillclimb. Like Loeb's overlay better, gives you a check mark when you did the joker.
as for tutorials, all have them, but each different... dirt is just videos, good informative videos, more about the sport then gameplay. Loebs has your play area and a opening walkthrough. WRC has a tutorial series but sucks, you watch then do. but if you don't do just right, and not sure what I've not done, you don't move on. Stuck on the 2ns tutorial mission.
so... real rally fanes WRC5, Loeb fans, well you know, a must have, all about him... DIRT, well so far, early time with...the best one. Overall.
sorry, quick thoughts not article proof.