My thoughts after visiting biggest KB showroom:
1. Leather seat is standard merc leather seat, which is good. Been in few mercs overseas. I think one grade higher than SNR3. need to confirm with mat79 I sat there 2 mins at front seat, feel can sleep. Not slippery. Very comfortable. Could not detect which Proton model the seats came from. Rear seats are new design. Front seat, not sure.
2. Finally rear leather seats that don't require you to cabut the headrest to make it lay flat. Last time my savvy need to open headrest, then can make it layflast. Some car makers do a slightly simple version where the headrest can fold forwards to fold.
3. Signs of wear and tear at glovebox hinge (after opening glovebox). This one can only be caused by someone viewing the car who did not lift the handle and more like tried to yank it open. Still surprised it is still firm. Glove box opens slowly, not directly open, sign of premium.
4. I still think "C" shape better than "L" shape rear lights, but the missing piece is used for the reflector. That is personal preference. Can live with "L" and "C". I think within a year, there will be aftermarket selling "C" shape.
5. Rear seats almost as big as Preve, did not feel small. Centre console does the job well.
6. Boot is actually quite big for hatchback.
7. No other fit and finishing issues like the picture at centre console. The side panel at the airbags have very minor inconsistencies, unless you look very very carefully not going to see it.
8. Seatbelt have fix height. Not changeable height like Perdana, 1st gen Savvy. Height set at "middle" setting equivalent for adjustable seatbelt. Not an issue if you already been in Preve.
9. Leather trim goes to gear, brake shifter, wheel. Finally a proton steering wheel which I enjoy touching without needing to go to an accessory shop to get those aftermarket covers. Better than the Inspira P, or the Perdana V6. The wheel itself has not changed, only the material used. I dare say even better than the Accord 2.0 which has no leather wheel.
10. That piano trim is love/hate issue. Fingerprint magnet. Aside from that, I don't see any issue. Proton directly copied the idea from the Golf MK7, which I don't mind at all. Paddle shift nice "click" to it. Inspira/CFE paddles look dull in comparison. Steering wheel is just height adjustable and not telescopic.
11. Nice two tone rims. I am very surprised if someone changes this for aftermarket rims. 17" wheels are what the Sedan needs. Now you can say wheel match with arch.
12. The silver dashboard is better compared to the light brown material used. In fact CFE also seems not that good, though I suspect that is more towards colour tone issue. You cannot just have one slab of "wood colour" trim for the dash and not continue to the doors like the Preve. It gives a sense of cheapness and upsets the colour balance of the car. That is why BMW have matching colour sets for doors as well.
11. Roof lining, dash buttons, autocruise, similar with Preve, Inspira as far back as the 1st gen Perdana (for autocruise button) and like all other cars. I forgot to see the mirror adjuster buttons. If same as Preve, then it has been the same since the first gen perdana as well.
12. I saw 3 hooks. 2 at side pillar for rear passenger, one at centre console for front passenger. Not sure if there are more.
13. Did not try the Android HU. Car was not on.

Conclusion:
Overall fit and finish is better than Preve. I already had the suspicion that HB will be better than sedan, but difference is glaring. Preve CFE seems like beta version, and this is ver1.0. Which begs the question, why was this not on Preve in the first place? This also enforces the notion that the best value proton car is the facelift version. Technically the HB is a Sedan facelift with a shorter boot. I bet you can buy this car without even worrying the faults. For those who can wait even longer for sedan facelift, then it is safe buy. All bugs reported by the current Preve owners. Unless you need the boot, I will give the HB a very serious look. I can understand the HB is heavier, slower, more fuel but additional airbags, leather seats, 1" rim size up will affect the weight. Only thing going for the sedan ATM is the Rm3k+ rebate over its standard 72k price. That may be a factor.

The HB Excutive will only come sometime November or was it September, forgot what SA told me. Too busy enjoying the car and too busy trying to find faults which was not there.

On another note, the Proton salesman confirmed with me that Hong Leong bank already wants 20% DP for car. Someone already mention in this thread. For this car, you will need RM16k for it-if going with Hong Leong. Other banks coming soon I here, despite BNM insist on its FB site not coming. Even the SA fully supports the 20% so that people will default less. In fact, 3/4 of the time he spent talking to me about the DP issue, as I wanted him to stop talking about the car and raised that 20% so that I can concentrate on the car and not some DP.