I am a graphic designer, who has been using this lovely tool for many years. I think I stumbled across this site when at least 6 or 7 years ago. I'm so glad I discovered it as Indigo was really a catalyst for launching my career in the creative industry many years later as an adult. I graduated college a few years back and have been marketing myself to various agencies here in the heart of Silicon Valley. I am seeking to incorporate 3D visualization into my workflow and offer this as a unique selling point as a designer. As someone who is used to working within the Adobe Creative Suite, I find I have been struggling with Indigo after picking it up for several years of being away. The image quality is terrific, but as someone who is seeking to work in a fast-paced agency environment, I think a few UI changes would really help to make things smoother for me as well as other creative professionals. Here are a few things that I have been thinking of
1) Some feedback from Indigo when your scene has issues. I downloaded a scene off the Sketchup Warehouse, only to waste hours trying to figure out why it was rendering black. These sort of things cost companies time, and as they say time is money

2) HDRs are a bit tedious at the moment, as there is no way to get an idea of how they are position, and there isn't really a lot of control for adjusting them position-wise.
3) A lot of important controls that don't fit into any of the categories at the top (camera, environment) are hidden away in a huge list of items, which again slows down workflow, and makes it harder for us creative professionals to access important things.
4) No easy way to adjust the brightness of emitters. I know about light layers, but I want to have easy access to the output of my lights.
I just wanted to say thanks for keeping this lovely thing free for so many years. It has really helped me turn my childhood passion into a career. I look forward to hearing your thoughts.