You don't need to switch to photoshop to create your texture, your normal map or the displacement. You can bake directly onto the texture, create different layers et more.
Again, I am a modo fan. I love the app. However, I want to be fair as well. You are correct: you don't necessarily need to switch to Photoshop to create your texture. However, you cannot replace Photoshop with modo. I find that I must go to Photoshop from time to time no matter how good modo's paint tools are. This is simply because the tools in Photoshop are so much more advanced than modo's painting tools. Most of the people I know that use modo do a decent amount of painting for their models in Photoshop. They paint in modo, too, but find that modo lacks in some areas.
