We all (well most of us) complain about the cheap stereo, the "low feature TV", the refrigerator that doesn't cool as expected, the A/C's that won't keep the trailer comfortable, the furnace that's too noisy, the microwave that doesn't work properly, the water heater that runs out of hot water mid-shower, the faucet that we can't get our hands under, the shower head that doesn't provide a decent shower, the mattress that's not really a mattress, the furniture that's uncomfortable, the table that "rocks when you eat", the holding tank sensors that always read "full", the water pump that's noisy, the power center that isn't marked properly..... Well, you get the idea...... So, why would the "built in vacuum" be the only "top of the line" appliance????
As for installing one, the ONLY benefit (and it's not beneficial) to having a built in vacuum is not having to store it, but you still have the problem of storing the hose, attachments and wand. Plus, when it breaks, or when the bag is full, you've got to "crawl inside some cubbyhole" to replace the bag. Much easier to buy a quality (Dyson or Shark) stick vacuum, corded or cordless, your choice, based on where you camp and use the vacuum, and store it where you'd have needed to store the "hose and parts" for a built in vacuum.
Yeah, if you haven't noticed by now, I'm not a fan of built in vacuums. My limited experience with them is that if they come with the trailer, they are the cheapest, poor performance model from the lowest bid manufacturer and where they're installed, typically always smells like an old vacuum cleaner bag.... YMMV