We really love our frameless windows and they make the exterior look super cool. Wouldn't buy another TT without them....
The only issue we have is that they interfere a bit with our two entry doors and we can only open them about 1/2 way otherwise the glass hits the door.
The bottoms open out maybe about 3", and give plenty of air flow. You get more privacy too. With our tinted windows, when fully open, people on the outside can't see in as easily compared to sliders which have only the screen to see through when open.