Vacuums: don't get sucked in.(Buyers guide)

Bagless design, HEPA filtration, and the colorful, high-tech look popularized by Dyson have helped vacuum sales hit 20 million last year. But changes, our tests reveal, aren't always improvements. Some models still leave too much behind, spit it back out, or are cumbersome to use and carry.

An example is the rejiggered Hoover WindTunnel Self Propelled Ultra. Its HEPA filter has been replaced by a flimsy filter and a HEPA bag, which is supposed to trap dirt. But dust leaked from around the cardboard seal of the bag on this model, and the non-HEPA filter proved too little, too late to trap what escaped from the bag. This vacuum's emissions score dropped to fair from excellent.

Improvements are also driving up the prices of some vacuums--many of our top-scoring models cost $300 or more. You can spend less than that for fine performance, but you may need to settle for a noisier vacuum, one with fewer features, or one that's less convenient to use. Here are some other findings:

Some ideas don't take off. The Airider canister vacuum floats on a bed of air, so you don't have to tug it along. Though it's relatively quiet and excellent at cleaning bare floors, little clearance below the hovering canister led to snags on door saddles and when moving from bare floors to carpets. Its hovering also blew some dust into the air, and its lack of a powered head affected carpet cleaning.

The bagless Hoover Z 700 has a folding mechanism that, according to the company, gives it the "performance of an upright, the flexibility of a canister." But we found it heavy and relatively hard to maneuver. And at $500, it was much more expensive than our CR Best Buys.

Vacuum makers shuffle lineups. Two of the four models we judged Not Recommended in our March report have been discontinued. Hoover redesigned two weak clips in its Duros canister model. So it's back into our Ratings with a very good score. But Hoover's Fusion upright remains Not Recommended because of high dust emissions. We also added the upright Eureka Optima to that list for releasing a plume of dust during our tool-airflow test.

You asked, we tested. Several dozen reader letters suggested that how heavy a vacuum is and how easy it is to carry should carry, well, more weight in our ease of use scores. Now it does, and we've rescored some of our models as a result.