Before and when we moved here we had one of those Rainbow vacuums that sucked the air thru water and you dumped the dirty water in the toilet.
Not long after we moved here we had a vacuum salesman come by and demonstrate. We thought the Rainbow was really getting all the dust. He put a photo flood on the exhaust of the Rainbow and you could see the dust that was coming out. He said the dust that was coming out was dust that was going thru the water like you skip a stone. Put the light on his and you couldn't see anything coming out. It captured so much and such small particles if you just let it run without the hose as an air filter it was certified as a medical grade air filter. It has a 1 micron heppa filter
Then he put a tablespoon of baking soda on our carpet. Vacuumed with the Rainbow until we said we thought he got it all. Then vacuumed with his and showed us it pulled up almost a whole tablespoon of baking soda AFTER the rainbow.
I bought it with a week to change my mind. During that week I went a bought 7 other vacuums that were supposed to be really good vacuums. i vacuumed an area with each, then went over that same area with this one. It ALWAYS was able to get as much or more up after the other vacuums as they did. Took them all back and kept it.
Noticed after using the new vacuum for a couple of weeks there wasn't hardly any dust collecting on things in the house like it was before as well.
When we got the maid she wouldn't use our vacuum and instead used her Rainbow. She said it was the best. within a few times of her using the rainbow I noticed more dust collecting on things again, BUT I didn't say anything because she was doing the dusting as well.
My favorite vacuum was the maid doing all the vacuuming and dusting.