When buying a planer the first thing you have to ask yourself is exactly what will you be doing with it. You also need to know that a planer alone will not flatten a twisted or cupped board, although you can make cribs that will help you with that. A lunchbox planer will flatten a board though somewhat better than a stationary planer. Most have neoprene feed rollers that do not exert as much downward pressure as the corrugated steel rollers on stationary units. Next, planers create a crazy amount of shavings, some shed them better than others. A dust collection system is the best solution, but many due run them successfully without one. They just use a snow shovel...lol. Finally I would look at blades type. How easy are they to change and set up. How expensive are they? Usually the lunchbox planers have carbide, which last longer and can cut more materials, or high speed steel. HSS is sharper, gives a better cut, but do not last as long and can not be used on certain materials such as mdf, multiple glue lines, teak. Stationary machines utilize carbide, HSS, or helical heads with carbide inserts. Finally I would read about adjustability. Snipe is an issue with planers where the first and last 2-3" have a little deeper cut. I believe DeWalt reportedly had a system that minimized or eliminated snipe, don't know how. For most of us it is waste calculated into the project. Good luck and I hope you find what works for you.