The Perfecting Blender Duo by EcoTools is a set of two sponges designed for different makeup application needs. Julie, the reviewer, appreciates the eco-friendly aspect of the product. She mentions using the sponges wet, finding them soft and easy to work with. The mini detail blender is great for precise concealer application, while the larger base blender works well for cream blush and highlighter. Overall, Julie loves these sponges and praises EcoTools for creating a high-quality product. However, the review does not mention any potential drawbacks or limitations of the Perfecting Blender Duo.