The short version

One technician's experience at NTI, summarized. This is my account and opinion.

I worked about 84 hours a week, seven days a week.
I missed my child's birthday and my wife's first Mother's Day with our little one, and I worked July 4th.
During orientation I designed the training rooms' audio/video system and got nothing extra for it.
I went to the emergency room with pneumonia and my employment ended, with absenteeism given as the reason.
NTI's Director of Training and Quality Control, Michael Raleigh, told my entire training class that the company plans to build a BICSI training facility and run an in-house course for new hires, taught by NTI management, to get as many employees BICSI-certified as it can, and to make BICSI easier to get there than anywhere else. I know of no other shop with that setup. More on BICSI.
In my time there I never saw NTI hire an apprentice, and I saw it use temp-agency labor to fill roles whenever it could.
I asked NTI to do right by me on additional pay; they declined.
My PTO took five days to pay out in full. As I read the union contract that was late, but I never put it in writing, so I have no claim. Put pay problems in writing.
I have my bank screenshots and pay stubs and will share them with anyone who asks.
As I understand the contract, absenteeism was grounds for termination with no real exception for a medical emergency.

Managers I dealt with, in their professional roles: Cesar Arevalo (project manager), Brian Tucci (operations manager), Eddie Perez (HR representative). They and NTI may reply and have it published unedited.

The lessons are in the checklist.