also things like this happen in editor testing but in a compiled game its very smooth. I added one set of stairs to a massive level i made and it dropped the framerate to 25-27 when tested, but when compiled the level ran at 33fps on a comp with 512mbram and it was built on my machine with 1 gig.(wich had the framerate drop in testing) So don't be fooled about testing speeds, remember, you have the game and editor running simoltaniously. If framerate drops when adding one object, build a compiled version of that level, close fpsc and test the compile, you may have nothing to worry about.