I worked for Bechtel arround 3 years. So, my experience is as an insider and genuine.
However, different people can have different experience with same company.
Everything has its pros and cons, and Bechtel is no exception to that.
First I will share the pros of Bechtel:
1) High salary: Bechtel is one of the highest paying company of its sector.
2) Building, sitting arrangment, software, hardware are of high quality.
3) If they have work, they give on the spot offer letter.
4) Good exposure: Big clients, big projects. That is why, I have given 4 stars to career growth.
Now, lets discuss the cons:
1) No job security: Firing is very common. Ghat is why I have given 1 star to Job security.
2) No clear criteria for firing.
3) No differnce between a permanent employee and a fixed term contract employee in terms of job security.
4) Junior leve engineers are used as Scape goats amd treated with disrespect. That is why given 2 star to work envirnment.
Conclusion: You can join Bechtel if you want to get top salary in the sector, but at the same time you are ready to sit jobless at home for sometime, until you find another job.