The Complexion Blender Brush by Real Techniques receives high praise from Grace in her video review. She compares it to a beauty blender and notes that it blends her foundation flawlessly without causing any dry skin issues, which she often experiences with other tools. Grace appreciates that the brush allows her to wear makeup without worrying about it exacerbating her dry skin. She highly recommends the Prep Beauty Blender Complex Blender brush and mentions that it is available for purchase on the Flip App. Overall, the brush seems to be an effective and gentle tool for achieving a well-blended complexion.