Hi,
Content path -/content/project/en/home/_jcr_content/root/content/responsivegrid/image.coreimg.100{.width}.png
- This will take care of serving images based on defined renditions without implementing any custom logic.
- multiple cache for same assets based on page where is it used.
DAM Path - /content/dam/project/test.png
- This will requires implementation serving images renditions based on DAM renditions.
- 1 copy of cache
Both has advantages and disadvantages but surely you should go with /content/project/en/home/_jcr_content/root/content/responsivegrid/image.coreimg.100{.width}.png
Arun Patidar

