Vantaggi
Compensation and benefits very good (recent 401k cuts hurt this however). Have a really generous parental leave policy, if your supervisor doesn't guilt you into not using.
Svantaggi
Management doesn't value differing opinions, and actively discourages change. Ranking process leads to employees being obsessed with showing any mistakes were not their fault and trying to fix only if the solution involves zero risk (which is almost never). No clear vision of the future - leadership at my plant flipped between spend no money and spend as much as we can (to capitalize on tax cuts) multiple times within a year for two or three years straight. Once inside it becomes exceedingly clear why ExxonMobil is severely lacking it's peers in earnings and ROI. In the field, long work hours are prioritized over effective work hours; leadership expects employees to make working for ExxonMobil the most important thing in their lives. Still an old boy's club; little career advancement possible without buddying up to management (not entirely unique to XOM). The chosen few would fly up the ranks despite an average to poor performance based on relationships with senior leaders. Zero concern for environment/communities they operate in - pretty obviously, it is ExxonMobil, after all.