The basic difference was the Tac Ticket got no ILS training and very little VOR work but lots of ADF, GCA, Holds, IMC takeoffs from the ground (No outside reference at all)....and standard NDB approaches and lots of Tactical NDB approaches that included NDB and FM Homing Figure 8 approaches.
For the sake of a few hours training on ILS's and a few hours less on the Figure 8 approach....we could have all had Standard Instrument Tickets.
Standard Instrument Ratings were usable in Civilian Airspace....Tactical Instrument Ratings not. In Vietnam did not mean much but once back in real World environments....it meant a huge difference.
The figure 8 approach was one where you did a figure 8 pattern with constant heading segments 15 seconds long after passing overhead the Beacon or the FM radio location (think down to Platoon Level untis using back pack radio's and keying the Mike for you to home to.
You descended all during the approach to arrive at decision height as you approached the beacon or homer transmitter.....200 feet was the minimum as I recall. Visibility was not a factor. Either you could see to land or not....and visual guidance would be assisted by Smoke Grenades, Flares, Flashlights, Zippo lighters or sometimes guys laying on their backs in small holes waving an index finger if it was a really Hot LZ.
I preferred to find the trees....and then home to the location or map read to the place or in extremes do the old "You are getting warmer talk down method".