There are great performers.
Sanitaire Direct Air, otherwise known as Dirty Air vacs are very good performers. They are powerful with great air flow and there are numerous brush rolls to choose from to suit your needs.
Many models have a Shake Out bag. That style was meant for commercial building cleaning where a company didn't want to purchase bags all the time. The power is there but the filtration is not. They are known for spewing visible dusts in the air during use, especially after dumping. However, you can get an F&G or ST disposable bag set up on them and have far better filtration for your home environment.
My preference is towards the 5 Amp ones. The 5 Amps had great power, they were very pleasant sounding and they actually cleaned mats and throw rugs, removing the dirt from them while not trying to eat the entire carpet.
The 7 amp ones are very strong performers and many feel they are a little too strong. They can have a tendency to stick to some rugs like glue and especially for throw rugs and mats, you may be looking at doing forward strokes only so as not to eat the carpet so much. Also, be warned that the 7 amp machines made in recent years have a much more shrill sound to them that is not near as pleasing to the ear compared to models made in the 80s, 90s and early 2000s. Someone else made have knowledge as to exactly when the motor change occurred for that series.
