I've had a heated unit for a couple of years, 2 thumbs up! It gets used 4 or 5 times a year on the cars and occasionally for in-house spot cleaning.
Reading a lot of reviews I get the impression many of the returns are due to the sprayers quitting due to clogging. I take the precaution of THOROUGHLY flushing out the unit each time it's used and haven't had that problem. I used to use the Bissell cleaning solution but have recently stopped using the cleaner tank altogether. I now spot clean with Folex and use APC+ 4:1 out of a spray bottle and only use the LGM to extract. I do use the cleaning tank for distributing warm water before extraction, everything seems to come up cleaner that way. As the hose could be a bit longer and the included attachments don't get into some of the places I need to I always finish up with the Shop Vac on the cars. Very little drying time left using that method.
I'd also skip the refurbs. I picked up a LGM at Wally World on sale for 85 bucks. Shop around, they're out there.
It isn't designed to be a high volume, heavy duty unit but it works well for what it was intended. IMO, keeping it cleaned out after use enhances longevity. YMMV.
TL