i have two contico ab810s,
the first time i put one "under" the carpet, the whole carpet lifted 2- 6 inches upward towards the heavens, the only thing holding it down was the furniture.when id finished, i had to move the furniture down one end and re-stretch the carpet back onto the gripper...id put the snail on the most powerful setting! - ONE THING ID SAY IS THE LOW SETTING, is very handy on the contico, 950 rpm, yet still a powerful machine...my friend has a karcher one which is a £100 cheaper than the contico...worth a look perhaps...