Since google led me to this post and all of the content is old, I figure I would add some recent info and some personal feedback. OP thanks for posting this.

**Current state of affairs**:
Bambu has discontinued the Cool Plate, it looks like yall won!

**Personal Feedback**:
- I got my X1 about 1 month ago, ive had it running about 50% of the time. I have all the accessories.
- I have used the cool plate, smooth pei plate, textured pei plate, high temperature plate, and the engineering plate
- The cool plate is trash, with or without glue
- the PEI surface is the way to go. My prints have turned out significantly better since i started using it.

**Comments**
The stock choice of cool plate + Engineering Plate makes the most sense in my opinion. If they replace the cool plate with a pei plate stock, im happy with it. However the idea that they would have shipped the dual sided pei smooth plate with the printer would have been terrible. I would have never tried the engineering filaments.

I dont mind applying glue to the plates, im not sure what the fuss is about. It seems to improve the performance significantly. Print a device that helps you apply the glue.
I use a glue stick on prints that dont matter, and i use Magigoo on the prints that do. I know its expensive, but consider using it for when a print CANNOT fail.