...although that's due in part to grievances I have with standard play sessions (that'll be for another post).
Well, as the discussion has swung around to motivation/burnout I'm going to elaborate on this and why I am currently in the 1 evening a week camp.
Out of all the previous Forza games the only one I've played aside from this was FH4 (and that shortly before it shut down), with the only online "races" I could play being the Eliminator due to some weird tech issues around matchmaking on Steam. That said I have watched videos of the older FM's and what I remember from those was that you could make some truly ridiculously powerful cars for their rating but with the downside of being an absolute strugglebus in corners. Obviously that was the meta for something like Le Mans but on more balanced circuits they were exactly that... balanced.
I talked about this with my brother after he grinded to level 100 in Online Play last month and he came out of that feeling that it was one of the most unbalanced online games he's ever experienced. Off-road events were
generally fine but his ire was especially reserved for road-racing and the current practise of AWD-Swapping higher-powered cars (Ford GT/Viper e.t.c) onto Off-Road tyres. They take all the straight-line benefits with very little downside in the corners, so much so that any cars he took out which had been "logically" tuned were left in the dust along with everyone else who weren't using those swaps, usually to the tune of 15-20 seconds in races that only last 2 to 3 minutes. It was especially prevalent in A-class which was a double-blow due to it being his (and many other's) favourite class... compared to his experience in FH4 (300'ish hours Online play) it was night and day.
Up until that point I had been doing experiments on the Goliath with D-class, specifically with the older cars on vintage tyres and finding the right balance for them (250+ BHP/Torque with vintage tyres on something that weighs 600-odd kg is NOT a good idea

). It had been quite enjoyable but after that discussion and looking at the leaderboards for A/S1 (by all accounts the same problem as above) I thought it would be a good time to pack that it in for the rest of the summer, especially if another leader board wipe happens... and I can't see it not happening, it seems just as much an exploitation of game/PP mechanics as the drag tyres were.
As it is, play sessions are now effectively 2 hours a week with my brother to quickly run the playlist championships and other assorted events with a couple online spec races or drift championships thrown in... (praise be to spec racing).