Orecks aren't terrible, in my experience, but they do lack power. They do well for quick clean-ups as long as something beefier is used in between.
Before they cut funding, the janitors at my office used Orecks daily to vacuum the offices. The carpets looked pretty good, but over time they started to get dingy in the high-traffic areas. They also had a Riccar 1700 canister that they used for bare floor areas - so I borrowed that and used the power nozzle, and it spruced things up nicely. Orecks seem to get the surface crud but they don't dig deep.
The 8 pound Simplicity/Riccar machines, though, are as handy as an Oreck but a lot more powerful. I think they're as powerful as a Kirby, honestly, though the lack of manual height adjustment means they don't do as well on odd rugs.
