Just wanted to mention my own experience with full sinking lines:
I used to use Teeny lines for fast sinking distance casting but could not cast, no shoot, the distance I wanted. One of the reasons was that the thin shooting line got tangled at least 5 out of 10 times, which really irritated me. Also the head would often hit the water in a "not straight" way. Probably both due to my own inabilities in casting.
I then tried to keep more line into the air thus shortening the length of line to be shot. Needless to say that that did not work with a Teeny with a business end of 24 ft.
I switched lines to a Rio DC Full Sink and found that a lot more line could be kept in the air, even to extreme lengths: I shoot out line on my last back cast up to about 60-65 ft and again on my last forward cast. This way it's often possible to cast the full line out of the tip ring (rod used has a fast action (TFO TiCrX 8) with a #9 line, cast with a very tight loop)
Is this really strange or do others also have comparable experiences?