My D goes to Pomona. I went to Stanford. Truthfully, she would have gone to Stanford if she had gotten in (deferred EA, then rejected). But she is very happy at Pomona and it is probably a better fit for her very low key personality. She turned down some really good schools (for example Dartmouth) for Pomona.
I have met many of the other Pomona parents - and I can tell you that the percentage of kids who are at Pomona who were rejected by Stanford is ridiculously high. There is a reason for that - Pomona has a Stanford feel to it - but it is smaller (much) and quieter (somewhat). Then again, 40,000 super smart kids are rejected by Stanford every year. It’s not a small club.
The OP has picked a school by now. But the idea that one could pick one over the other based on not getting overloaded with work is pretty funny. Pomona isn’t a super competitive place based on outward behavior, but most of these kids are very motivated and put a lot of internal pressure on themselves to do well.