Avantages
World wide work hence can chance to interact with the world , abroad visits, Working on latest technology , technology awareness, Most of the development projects are under proof of concepts and working on those projects or rather I say you can contribute to companies growth while working on another billable projects.
Inconvénients
Managment is not cooperative , Although you get heired for some technology but it's not true that you will get to work in the same. If you are a developer and if the company doesn't have development project then you may be asked to work on support or any different technology. If you get single escalation or few then salary hike will be up to the mark . Internal politics is another concerns. Questions may get raised on your work although you are working honestly and hence you always have to create proofs of your work.