The thing that makes Forza 5 so gross is that, in Forza 3 and 4, you'd get free cars all the time (every time you gained a level), and levelling up those cars would get you discounts on all the mods and upgrades you could buy for them (eventually you'd get free upgrades, IIRC). Forza 5 does away with all of that, making you buy every car and pay full price for your upgrades, and then it fills all the menus with prompts to pay real money for virtual money (in the GB Quick Look they showed two on the same page at one point). It also has about half the number of cars and tracks as its predecessor, and a few cars from previous games are paid DLC this time around. And when you buy those DLC cars with real money, you still have to pay virtual money to unlock them in the game.

GT6 sounds like it works exactly the same way GT5 did, though, with prize cars all over the place and a pretty easy-going economy (as well as more cars and more tracks than GT5). The fact that macrotransactions are there at all is a shame, but it does at least sound like they're easily ignorable. I haven't actually played either game yet, though, so I have no idea how it gets when you're fifty hours deep into your racing career.