Google

Work with great people, an awesome salary, and benefits. The place is chock full of good people.

There is a very advanced internal software infrastructure for you to learn about and use. This infrastructure will be more capable in many ways than any place in the world.

And Google has world-leader workloads. Everyone says that, but it's true for the big G.

It's hard to deal with being average, especially if you were a super-achiever in your old job. Most of the not-great people were weeded out at interview time, as well as many other good people.

The company feels like it's lacking in career advancement possibilities. Advancing requires working with more highly-rated people to rate your review, and there are a lot more of them in MTV.

The Seattle offices almost certainly have:

• More experienced people than other offices (MSFT, AMZN)
• A lower promotion trajectory because it's more competitive.

It's common for recruiters to say, "We rejected this person for Seattle, but we'll take them for MTV."