Vantaggi
They have a high turnover, so if you are in desperate need of a job, you can probably get one here. You can be exposed to the construction industry and get a basic understanding of what the job entails. The people you work with will be (generally) competent and able to show you the ropes.
Svantaggi
Wow, where to begin... The company had completely turned over before I was hired on, red flag number 1. Everyone that was there had only been employed for 6 months (max), red flag number 2. The company could not be more dysfunctional. It was the most micro-managed firm that I have ever worked for. No ability to grow and learn in any sort of reasonable environment. The firm that I was subcontracted to took on all of the training and I really established a good working relationship with them.
If you are in a bind and need a job, go with ACG, but update your resume and get ready to find a job very quickly after you start. Within a year after I left, everyone that I worked with was gone. Very poorly run company. Get what you can from them then find anywhere else to continue your career, just my 2 cents. This was a great learning experience for me in the sense that I developed serious boundaries between myself and employers I've had since then.