I am pretty much with you on the pros and cons of the challenge as stated in your post. And though I have a 9 to 5 job, I still managed to only skip two days.
Like many I found burnout to be the major issue. There were also days I felt as if a piece could have been better were I given an extra day or two to revise it. But because it came down to meeting a deadline I had to rush some of them more often than not.
Despite this, I was still grateful for the challenge. I never thought I could write 98 poems in 100 days. It also forced me to read a lot more poetry than I am used to. I also read a wide range of poets than I normally would. And while I was not able to read them as deeply as I would have liked, the fact that I have been introduced to them means I can go back to reading them and see how I can develop my writing.
Overall. It was a positive experience, especially seeing that I have met some people who, even now, continue to read my work.