t tail
conclusions
aerodynamically keeps the horizontal tail clear of the wing wake, and this means no turbulence (and only 2 corners), so it is the cleanest of all, and there is a better reaction and sensibility. based on my experience, as i have 3 planes with it, i can confirm this. full size planes, especially sailplanes, use it extensively, and passenger planes like de havilland dash 7 and 8 too, so must be a strong reason for that. another thing is that it can be placed with the leading edge slightly ahead of the fin's leading edge, getting a cleaner entry-and improving even more its efficiency. an example is the ask 21. see http://www.alexander-schleicher.de/p...k21_main_e.htm
installing it, the cleanest way is placing the servo at the fin. or you can use a cable, but this means some drag to the servo. to eliminate drag you can install a linkage with 2 belcranks, but it is more complicated.
also, it is heavier than conventional, as the fin has to be built stronger. but that could be very little if you do a good job engineering it.
and is more prone to damage if you fly competition and do those landings (crashes) to get to the spot-or if your landings are not smooth.
i have a 2 mt sailplane radian that has conventional tail (really it is a low 'x' tail) and it also behaves great, so at the end of the day it depends of what you like best.
i like better t tail for the aerodynamics reasons, and now i do smooth landings, but i must admit that you can live with any way that provides you good results, as long as you do a good installation with as little drag as possible and land smooth.

from the beginning of time, man has dreamed of flying. the wildest of all dreams. and for those who are into this, flying is an adventure. the final frontier. just being able to fly an airplane is all that it is. and for models there are several ways to do it: starting from the easiest, to get an rtf (ready to fly) plane, to an arf (almost ready to fly), to build it from a kit, to build it from plans, or to design your own, the goal is the same: to be able to fly. to experience that thrill of controlling it if it is radio or control-line, or to watch it flying, if it is free flight. of course, having total control in 3 axis that radio control gives us is the ultimate experience of fully controlling it (that is, if-or-when you are able to do so). but even if you are not having total control of it due to being learning, is still a wonderful feeling. i know, sometimes things may go wrong, but that is another thing that adds to the fun. if you could count that everything is going to go right for sure, it wouldn't be the same. the unexpected is the key factor that adds to the feeling of adventure.

but, oh what a glorious feeling, don't you think?