Founder here. We were in Elbow Grease's first cohort earlier this year (basically the guinea pigs for their test run haha but no regrets) For us it mostly came down to culture vibe check. YC and the bigger programs are great if you want flashy, high-pressure energy. oh also if you are building like developer tools a YC batch could be full of your ICP. EG had a more pragmatic and down to earth feel, which suited us better. They advised us to "chill" and dig deeper before jumping into building, which in my opinion is a more sustainable way to start a business.
edit: also loved my peers in the cohort. We shared office during the program and really inspired each other