Bag or bagless -- that is the big question when it comes to buying a vacuum cleaner today.

Some people prefer dumping a bin rather than fiddling with a bag. But it does create dust.

That's why Consumer Reports home and yard editor Bob Markovich says you may want to think twice about going bagless if you have allergies or respiratory problems.

"Emptying a bagless vac's bin spreads lots of dust," he said. "It's really a dusty mess when you empty those."

Plus, he says, bags tend to hold more dirt.

One more important decision: canister or upright? Uprights are the biggest sellers. They've tend to do the best job of deep-cleaning carpets. Plus they're less expensive than canisters and easier to store.

Consumer Reports tests show a few canisters now equal uprights in performance. The $600 Kenmore Intuition model 28014 was the top-scoring canister.

"But if you've got lots of carpets and you really want the best carpet cleaning, except for a couple of canisters, you are going to get better carpet cleaning out of an upright."

Canisters are best for cleaning stairs and sneaking under furniture.

Vacuum makers are adding lots of features to their models. Some are useful; many are not.

I asked Bob Markovitch, yard and home editor at Consumer Reports which features he thought were important. He said manual pile height adjustment.

"And that's really good because it lets you lower the brush for carpets and raise it for floors," he said.

Markovich also likes an on/off switch that let's you turn off the brushes when you're doing floors.

"So that prevents scratching, but it also helps prevent scattering debris."

For its October issue, Consumer Reports tested more than 80 models. Overall, uprights are better on carpet. Canisters are best for floors, stairs, drapes and upholstery.

Models with bags can hold more dirt than bagless vacs. They also spread less dust when you empty them.

The editors say the $350 Roomba Robot was "among the worst at cleaning edges and corners."

The Bissel Pet Hair Eraser did a good job picking up pet hair, but the magazine says, it was "less than impressive at other tasks."