They all work the same way. Where the "bells and whistles" come in is the price you will pay for the outputs on the converter. A basic converter converts the digital signal to the industry standard for analog and will provide a coax and a composite with sound. Plug it into the TV and tune from the box.
If you have a digital/HD TV without an ATSC (digital) tuner you can get an upscale (read more expensive) converter with component or HDMI outputs. If your TV has these inputs the picture will be digital/HD.
I've got my digital TV to analog converter coupons today and so I'm very interested in checking out what's out there and what's the best for my dollar. Are there any comparisons of over-the-air digital TV to analog converters?