Exponential allows you to create a more linear movement with your servos when you move your transmitter stick. Yes it "softens" the feel around center, but that is because the servo arm moves the fastest at center, versus at the end of its travel. When you add in an exponential curve to the transmitters signal output, you're slowing the servo down at center and letting it return to full speed at the end of the stick. Expo is very handy in helping out sensitive models, and if an airplane suggest it then it's best to use it.
We actually have a few different transmitters in our lineup. The Optic 5 is as bare bones basic as it gets with no programmability. The next step up is the Flash 7 which is a entry level computer transmitter with a wide range of programability. The next up from there is the Flash 8 which adds more programmable options, better gimbals, and an additional channel. At the top of our lineup is the Aurora 9X which offers the most programability in our entire transmitter range, and features an easy to use touch screen. It also has a very intuitive model setup function that walks you right through setting up your new model, leaving you to only need to program a few minor things such as rates/expo, and/or switch assignments.
My suggestion for you is the Flash 8. It's not overly expensive, it's easy to program, and it will allow you to grow into different models. We actually have one on scratch n dent special right now. There's nothing wrong with it, it just has had the screen protector removed from it.
HITEC FLASH 8 / OPTIMA 9 RECEIVER COMBO (SCRATCHED AND/OR DENTED PACKAGING WITH POTENTIAL PRODUCT BLEMISH) - WEEKENDER WAREHOUSE