here is what is not clear to new buyers.... a "T" or "C" 12... is it only the handle difference or are there other differences?
I don't know of any difference in a current model T 15 or C 15 other than the configuration. The difference in the configuration to me is somewhat significant...
Most people in the 'States are used to T-drills so that's the style they like. The C-drill configuration is a bit unusual here. The only ones that I recall from the past were Panasonics and they were really good drills.
The main difference in my opinion is when you want to push on what the drill is turning. Whether using a drill bit or a driver bit, sometimes you have to push pretty hard on the end of the bit. If you are using a T-drill and you want to push hard on that bit, you'd better use two hands - one on the trigger and one behind the motor so that the one behind the motor is pushing down the axis of the bit. With a C-drill, using only one hand, you can pull the trigger and push down the axis of rotation.
There is another consideration and I never thought about it until it was pointed out by someone on this Forum. When you hold a T-drill, your hand is farther forward and when you hold a C-drill, it is somewhat farther back but not much at all. This could conceivably add to the total length of the drill but I don't really think it's a consideration. I have both a C 15 and T 18 and just checked that theory. I don't see a significant difference.
I hope that helps. I can go into more detail and use visual support if needed.
Tom
EDIT before posting: Kev posted this while I was writing...
you really need to put these drills in your hand
That might well be your best advice.