Using a large capacity USB stick as iTunes Library - recommeded?

My iTunes library is currently 220 GB and is kept on a less portable external drive. It works fine but there's the inconvenience of being 'rooted to the spot' with this mains powered drive. I'd really like the portability of my laptop back, without having to disconnect my music library. Therefore it seems in theory that ones of these cheap, 500+ GB flash drives would be the way to go - or are they? Has anyone got any experience of them working OK? Do they cause any lagging when playing the audio? Do they tend to stay connected OK? Is there a particular way to format it to get the best performance? Would any old cheap stick with that capacity do the job? I have no idea.

I know I could buy a WD drive or something that doesn't use mains power, but having a small stick in a USB port would be better, if it's not a bad idea.

If you're referring to a ~500 GB thumb drive, be prepared to spend hundreds of dollars. If your just looking for a hard disk drive - not SSD - then you can get a bus powered one for 'cheap'. It will stream your music fine.

The biggest thumb drives around at the moment are typically around 256 GB. But there are known fake 500 GB sticks doing the rounds too. If you come across such a device at what appears to be a bargain price, I'd steer clear if you value your music.

I would avoid using a flash drive to store valuable music regardless of the drive quality. Portable flash drives are unpredictable and can fail or corrupt without any warning. External hard drives can also fail but are way more reliable than portable flash drives. When you have a music library that's 220 GB (I'm assuming you're a DJ) you want to be sure it's backed up. Losing a library that large could be disastrous and very expensive to recover from.

All drives will fail at one stage or another, and thumb drives quicker than any other.

Also people have a bad habit of not ejecting them properly and thus destroying the directory on them. Thumb drives are for occasional file transfer and maybe a backup boot "disk" -- nothing else IMHO