Pros
Flexible schedule (for me, at least). Free heating in the winter, free cooling in the summer. The people (non-management) are great to work with.
Kontras
Our site used to be Atmel, and after the transition, it just kinda sucks. We were given offer letters nearly 8 months after the acquisition, so we were told we couldn't get actual employee benefits until then (ESPP, bonus plans, stock grants, etc). However, we had to fill out performance reports for our prior year, even though we weren't considered employees by Microchip. However, in the email about the review cycle, it said we were all technically Microchip employees at the acquisition date, so the reviews were mandatory. Funny. Well, at least my shares will start vesting late 2018... Employee since Apr 2016, ha.