I rather use studio for building because:
- It’s easier (blender is pretty hard to learn and now there is blender 2.80 which destroyed my existing knowledge abot blender UI)
- I am not building photorealistic scenes very often
- Blender can be slow on older hardware. That was an issue for me when I had older computer.
If you are building something like a really simple car or a house then stick with Roblox Studio. On the other hand if you wish to build something photorealistic or more advanced stuff blender might be for you.