Since I was pushing my 7640u frequently enough for the temps and noise to be an issue (65-70c sustained temps with frequent peeks around 80-85c), I decided to upgrade to 7840u to keep me going strong for the next 2-3 years, hoping for something better to come along and bake to maturity.
The upgrade lifted my experience significantly. However, I ran into this issue where the machine would have a blank display on start/restart if it’s connected to a docking station, an issue that affected both 7640u and 7840u AFTER upgrading to BIOS 3.09.
I have a ticket open with support which is slow going to put it mildly. So, frustrated, I requested a return of 7840u and will continue working with support using the 7640u mainboard (while I still have it).
So, at this point, I had zero desire to upgrade. But, because the universe really wanted me to upgrade 
), up popped a marketplace post offering the Ryzen AI 9 HX 370 for $700 (that’s a $300 markdown on an unopened unit)! I jumped on the opportunity, and now waiting for delivery. As you can imagine, it was an easy decision considering I was happy paying $500 for 7840u a few weeks ago.
I’ll post my experience with the new processor once I’ve had a chance to play with it for a few weeks (estimated delivery date is 7/18).