I am very familiar with the NET guys, spent months working closely with them on closing a drug house, and know a few personally. Most are dedicated (full time) detectives, what (relatively) few there are left that is. Many of these highly trained, experienced, and specialized officers were put back in patrol cars because we were nearly a thousand officers short, because Phoenix would rather pay for trains, new museums and parks, and line the pockets of sports teams, than pay overtime for officers or hire officers when they needed to, years ago. The fugitive apprehension unit was completely disbanded and put into patrol cars. The drug enforcement bureau was disbanded. I know of several really great detectives who were put back in patrol cars, and it's a real disgrace. PPD is now hiring, and playing catch-up, but we have out of control heroin and meth problems and all of the crime that goes with that, and there is a lot of catching up to do.
Right now the 900 NET guys spend most nights cleaning up the area around GCU, because GCU has donated money to the right causes and persuaded the right people. 900, which is a huge precinct, has no NET squad much of the time, because they are tied up at GCU, and because the 93 NET team was completely disbanded and put back in patrol cars. Another example of the poor management at the top of PPD, and the City of Phoenix.
Yeah, they mostly use D deck, unless they are coordinating with other agencies where you can occasionally here them in the clear on inter-op talk groups, often on the South Mountain site.