Pros
-Great books. -Small company means that the office feels very friendly/collegial. -There are a lot of formal opportunities for mentorship and connection across the company. -I personally like the hybrid model the company chose (each imprint has two designated days in the office, which means that you're able to get colleague interactions/do in person meetings, but also quiet days to edit/read at home), but there are certainly detractors as well.
Cons
-Teams are generally very lean, so editors end up wearing lots of hats, and workloads are accordingly high. There are also a lot more meetings than at other houses, in my experience. -Generally doesn't seem that HBG is willing to go as high on advances as often as some other houses. -Some of the teams are really, really toxic, and HR/the CEO doesn't seem to be willing to discipline or fire bad managers. If you're considering a job at HBG, be very vigilant about investigating turnover and try to get some inside perspective before making a leap.