Frankly, the games look so similar (except a more robust career, your stage and additional disciplines) that I see no reason to stop playing Dirt Rally knowing they had removed so many countries.
I was incredibly hyped because I thought they were going to expand upon the locations from Dirt Rally and we would finally be getting 8-9 countries with many stages like in past games but instead of that we lost Monte Carlo, Greece, Germany and Finland and the location count went from six to five.
I think it'll be a good game but I can't see it surpassing Rally from a pure rallying perspective, it seems more like a sidegrade with a stage generator tacked on to make up for the lack of locales.