One thing to remember is that a portable is not the same as another portable. There are many basic portable extractors out there that may contain two vacuum motors and a water pump. However, manufacturers today have advanced the portable into a true carpet cleaning wonder. (See "The Truth About Portable Carpet Cleaning Machines").
When choose a portable extractor, the # 1 concern should be suction power. (See "Suction Power: CFM vs. Lift). By doing a little research, you will be able to find the portable extractor that gives you the power you want and the features you deserve!
Website Portable Recommendation: Eclipse High Powered Portable Extractor by CleanCraft Products, Inc.