Register fans (booster)

Has any one tried those register fans to put over or in place of your heating or A/C register vents in rooms? Our upstairs does not get much effect from our A/C but my wife stuck several fan over or next to the vents and a big difference was felt. My question, Home Depot sells one for about $35. Reviews are good but many people say the electronics don’t last. Anybody have other brands or reviews about these?