Oreck is a brand that seems to be unnecessarily divisive in the vacuum community. I think we often forget that as collectors, we look at things through a completely different lens as the end-user. Oreck did a few things really really well. Remember what was out at the time of Oreck's meteoric rise? Some of the most popular and well marketed machines were HUGE. Kirby Heritage II's, Hoover Dirt Finders/Concepts, were all HEAVY vacuums. Didn't matter if they were self-propelled, you still had to drag it out of the closet and plug it In and carry it up and down stairs.
Sure, Oreck's never cleaned as well as the big vacuums, but they certainly did a good enough job that the majority of people who bought them, loved them. You could get them under a bed, vacuum the stairs (not well, but you could get the bulk of the dirt), and actually move them around without getting tired. An interesting conversation I had recently with an Ex-Rainbow salesman comes to my mind. He was telling me that when he was selling Rainbow's in the late 80's, the easier house for him to pull dirt from was a house that had a Kirby. Not because they didn't work well, quite the opposite. It was easy to pull dirt because a lot of the people never used them. It was too heavy and too much work to put on the tools, so people vacuumed as little as possible. On the flip side, he said the worst house for him to pull dirt from was a house that had a Hoover Convertible. They were lightweight, easy to push, and thin. People actually reached for them regularly and their carpets were clean because of it. If your benchmark is a Kirby, you're probably better off vacuuming 3x per week with an Oreck that cleans 60% as well, rather than vacuuming only 1x per week with the Kirby.
Oreck found a hole in the market for a lightweight vacuum that could be marketed to older customers, and people who just generally wanted something lighter weight and easier to use. Sure it was expensive, something had to pay for the millions of dollars worth of infomercials, newspaper ads, and direct mail, but they created quite the empire for a few decades.
I grew up with Oreck's and had family members who owned them and loved them. Most of them had Kirby's and Concept's which still lived in the basement, but the Oreck was their daily driver. Sadly I think Oreck was a victim of being a high-maintenance vacuum. Realistically you need to change the belts every 3-6 months to keep them working decently, otherwise they would stretch so fast the brush would just stall the moment it hit the rug. Oreck was genius with the "Free Tune-Up" plan since it kept the customers coming back into the stores, but also kept the vacuums working well enough that customers really liked them. However there was a large group of these customers (like my family members) who lived too far from an Oreck store to get them tuned-up and would go years without belt changes (until I started doing them on a regular basis for them). Too often these machines would never get a belt and unless customers could remember how it worked when it was new (often they wouldn't. A belt stretching out is a slow-enough decline that most people wouldn't notice immediately, unlike a belt that has actually snapped), the machine would be used until they were unhappy with it and then go to the basement and get replaced by something else.
I guess to sum it all up, Oreck's in general worked well enough, long enough, that many customers were very very satisfied with these machines. At my store, we have a legion of devoted Oreck fan's who truly do love their machines. The XL21-customers especially really bought into the Oreck "lifestyle" and get their machines tuned-up yearly and really love their vacuum. The new Elevate Control and Command are just fine. I would still rather own a Riccar R10 Series because of their build-quality and performance, but the Oreck would suit me fine. Especially with the Command having the "Endurolife" belt which really keeps these machines working pretty damn good for a much longer period of time. Orecks' aren't for everyone (what vacuum is?) but they were suited for a lot of people who needed a lightweight alternative to their heavy uprights. Oreck really established itself as a well-known, high-end, home cleaning brand. It's sad they weren't able to evolve with the times and were purchased by TTI who has really done nothing with the brand.