Pros
The people that work here are great, diverse backgrounds and experience - lots to learn from each other. Lots of work coming in, and great relationships with trade partners. If you're interested in doing things mostly your own way, then the lack of structure and company standards should be good for you.
Cons
Completely disorganized and dysfunctional - everything still done pretty much pen to paper (Excel and email). Owner is a micro-manager and needs to oversee everything on every job, without putting any kind of trust in his PM's to make financial decisions. Some might call it toxic, but it's all surface level so at least you know what you're dealing with. Better than underhanded and passive aggressive toxic anyways.