Vantaggi
you learn a lot on the job and the other techs are very friendly and supportive if you ever need help. The office is always stocked with cans of pop or Aha. You get a lot of freedom in the field which is nice if you don't like being watched or micro managed. The huge variety of work and the locations that they go will expose you to a lot of the industry.
Svantaggi
They try to seem safe but often overlook issues. The work is either hard labor or it's tedious and needlessly over complicated. There is no HR department so if you do have an issue then you can just keep it to yourself. You will be sent abroad for weeks and while the Per Diem is okay, they will not pay it to you for a few weeks so you should make sure you have room on your credit card and don't mind having a balance. You will not be paid any extra for travelling as well. Often you will hear that they only will pay for 7.5 hours on mobilization days, despite your day being longer. You are not compensated for working harder or finding solutions. Your pay rate will go up as they see fit and negotiating isn't much of an option.