Pros
This is pure environmental consulting at a large company. You have to meet your metrics: billability, sales, net revenue managed, etc. If you are meet your goals and you deliver quality project work on time, you will excel here and largely be left alone to find your own destiny.
Do you want work life balance? That's up to you. Do you want to work hard and move up the corporate ladder? It is difficult, but opportunities abound.
No one is going to hold your hand, say how special you are, pat your little bottom and say "good job!". Ain't that type of place. Do you need to work long hours sometimes to deliver a project on time? Yup. Can it be difficult to deal with some managers? Of course. Is corporate red tape annoying and slow? Yes, there's 5000+ people in the company. It's to be expected.
If you don't like environmental consulting, don't blame ERM. That's the nature of the animal. If you enjoy its fast-paced, always changing, unpredictable nature, then this may be the place for you.
Safety culture is second to none, although it sometimes seems to border on the insane. Do I need to write a JHA to tie my shoes? How many partners must sign off to complete a boring 9 feet from a lawn sprinkler line?
Cons
Stressful. As much as they try, there is little connection between the higher up corporate leaders and those of us in the trenches. H&S culture is great, but can be over-the-top.