In my opinion, their payment model will not go down well with the masses, they are asking for trouble.
And to be honest.. when the mainstream realise that...
"To play privately with a friend will cost you 50c an hour....."
The **** will hit the fan.
Even more so when they realise the payment model is more MMO like as in "No subs, lose access to EVERYTHING you have purchased ingame".
rFactor 2 in a private league is a very good alternative.