Pros
X-Team is great, and they take serious care of their employees. We receive payments through international transfers, and I had a situation with my bank one day where my payment wouldn't be reflected. They were very kind in sending the payment again while I figured things out with my bank. They worked with me and took care of me, and I'll always appreciate the gesture. There are other benefits, such as:
interesting projects
payment is excellent
in-person networking with semi sponsored travels
X-team even offers certain job security by providing a grace period so a person can transition to a project whenever a project ends
For a person like myself, who's very committed to work, and I'm always delivering results, this job format works very well
Cons
Not really a disadvantage, but you gotta be on top of your game. Being a true senior engineer, deliver great results so you can either form a long term relationship with the client, or be able to transition through projects easily.