I worked at Juniper. Left because of management change. The manager I had was inexperienced and a bully. Went to Cisco. Was good there for a while and then, guess what? Management change and the same narcissist behavior started. On top of that there is always a fear of layoffs - people are very conscious about that and talks about it all the time. Tolerated the psychopathic management for a year and a half and then left.
Take away: Juniper benefits are better. Cisco has more elbow room and you can move around better internally as it's a much bigger company.
Common issue: if you are not a VP or a CxO, then in both cases, it's who you report to. Same as most other places.
Morale: same sh!t, different stink.