I feel I have put enough time in now to give my impressions on this game as it is in launch week.
I'll start with the positives: (Playing on Xbox Series X with a standard Xbox controller).
Visuals.
I think this is a very attractive game, most of the time. It's not 'wow' levels of amazing, but it is certainly good looking. The lighting at certain times of day and weather can be outstanding and the track environments are some of the best I have seen in any game, loads of detail, they feel alive when racing, they kind of remind of pCars 2/3 a little bit.
The car models are as expected for the most part, generally very good, the different materials look fantastic and there's clearly been a lot of work to things like headlights, finer details like grills and brakes etc. I have played it mostly on performance mode and it has stuck rigidly to 60fps during gameplay, in any weather and time of day.
Car Dynamics/Physics.
Playing with TC and SC off, ABS on, normal steering with a standard Xbox controller. Forza continues to be the benchmark for realistic driving games on a game pad in my opinion. The car feel and behaviour is still very obviously Forza, but the improvements can be felt, especially in racing cars. This I think is down to the improved tyre modelling, the race cars can be pushed much hard and have more believable grip levels relative to what they are. The cars bounce over rumble strips and kerbs a lot more convincingly and are less prone to snap oversteer.
Presentation.
Look and feel of the menus are superb, second to none. Very clean, excellent accompanying music, just really nice to use.
Gameplay.
The game is generally fun to play. I like the car progression, I like the in race feats and such throughout practice and racing itself, rivals is always good fun and an easy way to kill a few hours and so far the online modes look to be pretty good fun and will have plenty of life too. Despite the impending negatives below, the game is enjoyable, the driving is good and while there are frustrations with aspects which I'll elaborate below, it is a game I will put time into.
Now the negatives.
Track content.
Obvious one really, whilst I understand the need to rebuild the environments and that can affect total number at launch, the lack of layouts isn't acceptable. For this type of racing game, 48 layouts total simply isn't enough. There doesn't seem to be much reason for the lack of layouts either, with glaring omissions on reverse versions of fantasy tracks, and a load of real tracks missing long standing layouts, notably Bugatti Circuit at Le Mans, among many others.
Visuals.
Above I mention it's an attractive game most of the time, the times when it isn't, stick out massively. Certain lighting can do the opposite to others and make it looks bang average, with little detail or 'wow' factor. Pre and post race the cars can look low res and pretty ropey, especially i the podium bit. They also can look rough in the menus as well. GT7 suffers the same way and while I know it can be difficult to make bland days look good in a video game, it can be just poor to look at sometimes.
AI.
Awful, properly awful. Not in the, too slow and easy to beat sense, but in the completely stupid sense. They brake randomly while in straight lines or during flat out corners, and it's almost always while you're slipstreaming them, so you hit them and then get penalised for it, stupid. Super inconsistent between tracks as well, can be lightning fast around certain tracks (Nurburgring) and then very easy to beat on other tracks (Homestead road). Also, they made a song and dance about the AI being real with no artificial speeding up or slowing down of them, rubbish. Sometimes it's so obvious it hurts, Nurburgring, chasing a Mini in the Renault Megane, on it's tail for a couple laps, closing it down ready to pass, lap 3 starts and it suddenly finds 3/4 seconds a lap of pace..Plus the lead car always disappears regardless of whether it should be capable of it or not.
Audio.
Bang average. It's acceptable but it isn't a positive. It seems to have taken a big step backwards from FM7. There's no meat to the audio, the cars are too quiet, some of the car sounds are just downright bad and there isn't much dynamism to any of the audio. It doesn't make sense because previous Forza's, Horizon included, have been strong on the audio side of things, yet here, massive step backwards.
Gameplay.
As much as there are positives with gameplay, there are also negatives. Chief among which is there isn't enough of it. With talk of similarities to FM4 in terms of scale, not only does it fall short, it falls short almost laughably so. Not enough races in the 'career mode', not enough events in Rivals compared to Day 1 on every other Forza Motorsport game (where's the track day and autocross events?) , and the gameplay loop is almost identical for FM7, 6 and 5. So much for a reboot. I know, they're adding more to the game post launch, but honestly? That excuse is old, it's boring and it doesn't let T10 off the hook for just not having enough content.
The builders cup idea is interesting at first, but, you don't need to build your car to win it, which seems to defeat the purpose. I mean, obviously you can build your car up, but it isn't essential.
Final thoughts and opinions.
A lot was made of this being a ground up reboot, and in that sense, it falls short everywhere except the track environments themselves. There's nothing new or radical in the single player modes, the USP to career mode isn't even a requirement to complete it, the AI almost ruins the experience completely and it ultimately feels too similar to previous entries. That doesn't mean it isn't enjoyable to play, it is, it just isn't what I thought we were getting. It reminds me a lot of pCars 3 actually, just with less single player content. It's easy to get caught up in all the negativity and focus on that as I have, but the game is still fundamentally Forza Motorsport, for better or for worse.
I also feel, that there is something missing, and I don't mean the obvious stuff like tracks and certain cars. I mean, it feels like this game changed direction late in development. I look at the first announcement trailer, the leaked test footage and screenshots and I am convinced that this was meant to go a different direction. There were hints of team creation, free roaming garage, different characters, something more in depth and grounded in proper Motorsport, perhaps with a light story element ala Race Driver 3 or a team building element like the F1 games. Then they got cold feet, ditched it and went for the classic gameplay that we were starting to get bored of with FM7. There's hints of this with the inclusion of a 'race engineer', completely pointless addition as the game is now, but in a more team/story focussed single player campaign, perhaps would have made more sense. The footage and screenshots that showed a free roam garage with different cars in bays with the same livery on, also supports this. The lack of innovation in the game as it has launched sticks out like a sore thumb, I genuinely believe that Turn 10 were doing something radical and bottled it in the last 18 months.