[ToxicMegacolon]

> On hiring you get a signing bonus, in my case the value of this bonus made my comp almost flat for those 4 years if the share price remained constant.

Signing bonus is not unique to Amazon. You can get a signing bonus anywhere in the industry, along with a sane vesting schedule of 25% each year or a front loaded schedule to prevent 4 year cliffs.

> Vesting is inherently lumpy, and makes managing cash flow a bit more tricky.

It doesn't have to be lumpy. Google stocks vest monthly here in US. Also, how is it tricky to manage?