Do you like a new vacuum every few years?

Nope. I run that thing until it dies

No, I use ours until they die. I think our current one might be close to 10 years old now. It is a top of the line canister Kenmore from Sears.

I wonder what's causing that. I've never had a "musty smell" problem and have almost always lived in older homes. My condo building is well over 100 YO. 

Anyhow, I have an Oreck upright that's probably 15 years old. No smells and works like a charm. I've taken it in probably 3x over the years for a little tune up but that's it. I'm hopeful that it's the last vacuum I ever need to buy. I also have a smaller Oreck cannister purchased at the same time and that one I've never had to have serviced.

I have had my vacuum for 20 years and no desire to replace it.  It doesn't smell or act funny.  I can't imagine paying money like that every 3 years.. but that is me.

I would love it because ours smells musty and sometimes like burning rubber. But dh insists that we use it until it dies and I don't really have a compelling argument other than the smell. I kind of want to vacuum up a bunch of legos and rubber bands to see if i can kill it.
eta: our vacuum cleaner is well over 10 yrs old. I don't think I'd want to replace every 3 or 4 yrs. 

I was just thinking about this as I used mine yesterday. I’ve had it 5 years and it’s still going strong. I hope it never breaks because I love it so much. Doesn’t smell at all and I have an extreme sense of smell.

I've never heard of that issue with vacuum cleaners.  We have been married 36 years and I am on my third vacuum cleaner. It's a Miele that is about 2 years old. The Miele before that lasted 17 years.  

Oh heavens no. I could think of a hundred other ways to spend that kind of money.

I’ve only noticed funky smells from vacuums that have bags. I never really noticed an ongoing smell from any of the bagless vacuums we’ve had, but I do tend to take it apart and clean out the canister really well with white vinegar a few times a year.

Not quite 20 years (more than 15 though) but ditto.

Try a vacuum with bags and filters. The bagless vacuums always stunk to me, so we moved to bagged. Such a difference as the bags act as a filter, too. If the vacuum smells a little dog-like, a bag change always fixes it.

Like others above we run vacuums until they die, too, except cheap parts keep breaking making them unrepairable (planned obsolescence). So when our last one broke last month, we upgraded to an actual repairable vacuum. We decided on the Miele cat and dog version, and the filters and bags on this are like Cadillacs I swear. I was absolutely shocked at how thick these bags are. Go check this vacuum out at a dealer. We haven’t filled our first bag yet, but I really doubt it will ever smell.

No, I clean my Dyson.  Had it since 2004 and still works fine. 
Now, bed sheets--I replace more often. I'll use one set of sheets--wash weekly and put back on the bed.  But I definitely replace more often than 15 yrs!

My sister is a vacuum killer -- she killed two Dysons - last April she killed my Dyson ... she buys only less expensive vacuum cleaners now since she kills them -- can't say "cheap" because none of them are cheap!
Don't ask -- I do not know why -- she actually takes better care of her vacuums than I do -- she took better care of my vacuum before she killed it.