I own a first generation Domane+ (65Nm) and just test rode the new Domane+ SLR $9000 with the tQ motor around the empty trek store parking lot for about 10 mins.
1) As expected, the bike is more nimble with its lower weight, less bulky motor underneath and 800 series carbon frame.
2) The power up/down buttons on the handle bars are ergonomic and really nice.
3) It had 32 mm tires, which are a nice midway between gravel 35mm and the 28mm road bike tires that most lightweight non e-bikes come with.
4) The motor is certainly quiet, but I dont find the Bosch motor to be noisy, so I may not be as discriminating as others.
5) I found the three power levels limiting. My Bosch has 8 and each has unlimited customization through the Nyon headset
6) I found the most powerful assist underwhelming, especially for the limited range that the battery has at that level.
If you are a strong rider (which you are likely to be if you are buying a $9,000 bike) the tQ motor will be fine as an occasional assist.
You can certainly ride this bike undetected with other riders because it's quiet and the motor isn't visible.
But if you live in the hills, or are a more casual/older/medically limited rider the bike doesn't offer enough assist to justify the price.
For me: If I'm going to bear the burden of the extra weight of an e-bike, then I want the option to occasionally use serious power to get me home if a) I run out of strength, b) run into headwinds, rain, darkness, or c) actually win the race. I'll keep the Bosch.