Interesting post. I found 25/5 too short so I switched to 50/10. I did that for a while but found 50 too long so now I do 45/15. It seems odd that I only work 3/4ths of the time but after meticulously tracking my hours worked (I'm a data nerd) I found that I work (intensely and focused) for roughly 3-5 hours/day.

My goal every day is to get 6 blocks of 45 minutes, which is 4.5 hours of real work. Seems sufficient for me so far ...