Pros
Everyone is super easy to get along with. I learned a lot as a junior hardware engineer, and left as a capable engineer. I am re-hireable, and left on good terms with everyone at the company. The owners are invested in the employees well being, and expect a solid 40-45 out of you. There was no answering slack on nights and weekends. The owners, and a good chunk of engineering is very religious (LDS), but I did not feel like that affected our work relationship. It was a bit uncomfortable at times as a non-religious person, but not enough that I wouldn't consider going back and working there again. The compensation for mechanical design engineers is at the low end of fair.
Cons
The management structure is very flat. There are four directors, and zero managers. Do not expect a path to management here. They are very up front about this, however, and did not string me along when I said it was in my 5 year career goals. Owners are pretty strict on WFH. Be ready to go into the office 100% of the time, even if your job is easily doable remote. 90% of the engineering team is white dudes. When I left there were only a few women in the entire company, zero in engineering. MFG team is ethnically diverse.