We had a rainbow at one time. It worked pretty well but someone stole it before it had a chance to wear out.

Shop vacs are cheap but as Dave Swan says, you'll need ear protection.

We have a Hoover at the moment and it works well but the belts and bags are expensive.

The most important thing you can do to improve the longevity of a vacuum cleaner it to throw the teenagers out of the house. It is a technological device that is way too complex for their tiny minds.