As ever I'll look forward to this.
Regarding visuals, I looks excellent, it will benefit from nit having to support the older consoles so I expect this to be a very refined visual experience, the fact we can expect 4k60 with RT on during gameplay is the biggest indicator of this. Should be quite something.
I don't feel comparison screenshots are needed to determine whether it's got the right colour palette, I have eyes and neither GT not Forza nail real life colour. Everyone sees things a little bit differently, even photography isn't perfect with regards to different photographers colour balance etc. My first impressions are Forza looks a bit more alive, slightly more dynamism to its environment. Gran Turismo can have this but only on certain circuits, there is a tendency for environments to feel stale (Sainte Croix I'm looking at you). Kaz has always said Gran Turismo is his vision of a perfect world so it is meant to be clinical and clean and precise. Forza has always felt a bit more lived in.
Can't comment on physics but it sounds pretty promising so far. If the tyre model has advanced by as much as they claim and that translates to player feel and actual driving physics ((let's not forget, PC3 has a very good underlying tyre model, you just wouldn't know it). I enjoy Forza Motorsport physics from the past, I prefer the tyre and braking physics in Forza over Gran Turismo personally. But until we get hands on its all just words.
Seen a few comments on AI as well, this is something I've said in the GT7 forum as well, Forza drivatars aren't perfect, but I'd take them over Gran Turismos nobots any day of the week.
As for things I'd like to see them change/add? The Homologation system from FM7 needs to be ditched, it didn't serve the purpose it should have, it should have acted like a balance of performance system like GT, but all it did was force slow cars to the top of whatever class (touring cars for example, it just made the BTCC cars go to the top of S to compete with the MR Swedish touring cars and it ruined how they drove). They either need to do BoP properly, or, my preference, keep different series cars separate. If we have WTCC, BTCC and STCC cars, give them their own championships, you can triple the playing content and keep the cars relevent. There was a lot of talk of a refocus on the Motorsport aspect so hopefully they make the racing series' in career mode realistic and preferably without having to upgrade the cars.
Online needs work, I know there are some significant changes coming to online which will be familiar to players of GT Sport or iRacing so that's a good step, but they need to nail the formula for how the races are curated and again, like with single player, ditch the Homologation crap and keep the series' realistic. Also I hope they do better with rivals, keep more events changing in and keep it fresh, FM7 didn't seem to give much love to the rivals events outside of the VIP or the 2/3 they cycled elsewhere. Drift, autocross, focussed events really didn't get any love.