Is a home theater in a box right for you? Even the best all-in-one home theater kits represent a compromise over what you could assemble using discrete components, even if you purchase something in the same quality category. That could be problem if you're finicky about the system's sound quality. On the other hand, most HTIB systems perform well enough -- especially with movies -- to impress non-audiophiles.
Do you want five- or seven-channel surround sound? Five-channel surround is more common, although seven-channel surround helps place effects more accurately. While relatively few Blu-ray Discs and no TV broadcasts are encoded to support seven surround channels, many home theater receivers and HTIB systems have a signal processing mode that can recreate it. Traditionally, the extra two channels are placed in the rear of the listening room; some systems support two front "height" channels, with the speakers placed high in the front of the room.
Where will you put all those speakers? Depending on the type of home theater system you select, five to seven speakers plus a subwoofer have to fit into the decor of your listening room, and in relatively precise locations if you care about a convincing surround-sound effect. Some systems use small speakers that can effectively disappear in a room of average size. Other speakers are so large that their presence is hard to miss. If the aesthetics of speakers around the room won't fly and getting the most accurate surround sound isn't a must, consider an active sound bar instead. Several great performers are profiled in our report on sound bars.
Are upgrades on the menu? Home theater kits are built for simplicity, and some use proprietary cabling connectors that make hookup a snap. However, such proprietary connectors can make things more challenging should you want or need to upgrade or replace a component like the system's speakers sometime in the future. Other systems use standard connectors, rendering that issue moot, but they can be a bit harder to set up in the first place.