Pros
Varied electronics, mechanical, electrical, HVAC work. You get to be a jack of all trades and they have lots of schools to attend in Oklahoma city. A new hire ATSS can expect to top out at $60K/yr after the first two years. Work sites all over the country. Initial training is mandatory, even if you're in the industry already or are coming out of the military. The use of a government vehicle (GSA leased) is part of the work arrangement.
Cons
Some sites are located in remote areas that require loads of driving to get to. There are two kinds of techs in this group: the sites techs who travel a lot to get to their sites, and techs who don't have to travel. Pay scale is not WG or GS, it's something called "core comp", which has pay "bands" that roughly correspond to GS9 to GS11+, but doesn't really include the "steps" that normal GS/WG pay scales have.