Long time Honda owner (no mas) change to Toyota/Scion and happy. Many Civics, Accords, CRV, never again. Anyway, I traded in the new to me 06 Xa which was a fantastic car, just wanted to upgrade and that is what I feel like the Xd is. I drive fast on the freeway and in traffic and this car is as stated, feels more substantial, less darty, more powerful. Inside the console is ergonomic, there are a lot more standard features and I am 5'10" 200 lbs and no problem with room. In short, I believe the Xd is a great replacement for the Xa and I really enjoyed my Xa, half of the miles where on the open highway, the other half in Phoenix, the city of bad drivers...
The feel of the drive, driver positioning, the stereo, air conditioning (it's hot here in Phoenix) and the interior. I'm comparing this to the Xa and Civics.
Keep doing what you are doing Toyota/Scion. I've owned many many new Honda cars and Toyota wins flat out, hands down in all areas. It's odd but I don't have any suggestions, I think the Scion division of Toyota is doing a great job.