I have used a L and many many many hams use a L with good success on Top Band, they do work. From what I understand if you wanted to work more USA you might want the L over a T
But for dxing , I will stick with the T for now. The claim is a T receives better than a L . I have no clue . I use lots of Beverage antenna but then again the T does receive signals very good.
I am no expert on this subject but this my understanding of the antennas and experience I have had.
Basically the choice between a T and L is simple- they are both just shortened verticals. Go with the one that allows you to put up the highest vertical section. If you can put up either, go with the T.
Receiving isn't that important because you really want a separate directional rx antenna anyway.
KY6R: your web page says you had a dipole at 65 feet. Why not hang an inverted L from that tree?