ORIGINAL: 98Redline

The TruBall Tru Tension release pictured is a pure BT release, meaning that there is no physical trigger on the release (regardless of weather or not it has a thumb post). The release is activated by the rotation of the handle, which nominally will be due to the tighening of the muscles in your back, causing your hand to move without intentionally trying to move it. The advantage to learning to shoot this type of release is that when it is being shot correctly, the pulling action tends to be a long gradual buildup of pressure rather than a jerking action. This build up of pressure in the back is not easily associated with the bow going off so it tends to keep the association between the pin being on the target and pulling the trigger (target panic) to a minimum. What you end up with is a suprise release every time.

The lower release is a thumb trigger (Spot Hogg Cascade 3 finger), however it operates as a "relax to fire" type. As you noticed, you push the button to "set" the release, then relax your thumb and the release fires. IMHO this is not the best type of triggered release as the relaxing part can cause you to go softly into your shot instead of pulling hard into the wall for a strong shot.

Roskoe.....as a general rule, you want your releases set up with a heavy trigger pull. This causes you to have to pull harder and thus get a stronger release.
When shooting my BT releases or my thumb triggers for that matter, when I start getting ancy with the release, I typically go with a release that is set up slower or has a heavier trigger. This requires that I pull harder and go into the shot stronger, thus keeping TP to a minimum.