I use sketchup. I have used tridentstagedesigner.com in the past. Real easy to use , but very limited. I tried gunracer also, same thoughts.
With sketchup, you can twist, turn, flip, walk thru, measure, plus much much more. Many many options. 3dwarehouse.com/uspsa has all kinds of stuff to down load and alter or to use as is.
But there is a learning curve. If you just sit down a play with it, in about an hour you will start to figure it out.