Yes, it’s too heavy for me. I expected 1.1 or 1.2 kg for Laptop 12, as Laptop 13 is 1.3 kg. This is also mentioned here by someone. What caused the weight 1.3 kg of the Laptop 12?
- Lenovo X1 Carbon Gen 11 (14-inch) which I am using as my working laptop is 1.19 kg.
- StarLabs StarLite Mk5 12.5 inch (2-in-1 laptop or tablet) is 0.9 kg.
- iPad Pro 11 inch is 444 or 446 g. Of course iPad doesn’t include a keyboard.
I also care about repairability, upgradability, support, and Linux-friendliness. And the reasons why I pre-ordered Laptop 12 are much more than the device itself. So, I still believe Laptop 12 is my best choice for now. 
The current plastic case mixed with metal makes sense because of its cost and robustness, considering Framework’s primary target customers, students. However, if the plastic case mixed with metal contributes to the weight of 1.3 kg, I hope that Framework or 3rd party will create a lighter aluminum (or/and titanium?) case option for Laptop 12 in the future, which may be lighter than the current plastic case.