The T-Rig is like the SUV of all rigs we use, the weight is used for not only distance but can also be used for rate of fall as well, the T-Rig is also used to get into and through heavy vegetation and all sorts of cover, the purpose of the T-Rig is to allow the weight to get to the bottom quickly or quicker than your bait, in turn as the weight sinks to the bottom it slides up your line as it travels if you let it fall on a semi slack line, this gives the bait roughly 6 to 10 inches of weightless presentation, depending on variances of depth and weight choice, once the weight hits the bottom it takes a little extra time for the bait to reach bottom afterward, depending on bait size and chemical construction along with hook size, some baits will fall slower giving you a little longer weightless presentation, shallow waters really require very little weight, heavy vegetation and deeper water usually require heavier weight, pegging your weight takes away the use of this portion of presentation before making contact with the weight, which a lot of times is where you will get a strike and becomes more like a Carolina rig or split shot type rig, pegging your weight close to the bait makes it more like a jig type presentation, I never peg my T-Rig because I want that momentary weightless presentation from the fall as well as on the first movement before it makes contact with the weight.
The T-Rig is best suited for working cover, although it's a truly great presentation for almost anywhere, just like an SUV would use 4WD for better traction in rough terrain, this rig allows you to come through and over some pretty mean stuff with less chances of snagging, not that it is completely snag free but it does work these pieces of cover much better than many other rigs because of just how thorough it is, if you are working a brush pile or grass, keep in mind that the tail of the bait may want to grab or wrap around whatever your working, for example, a twist tail worm is less likely to come through or over a brush pile without getting tangled in which case a straight tail worm would be better suited for your presentation where as a ribbon tail worm might be better suited to work just outside of these rough areas.