[ikk157]

It is well know that SSD are not reliable as HDD when talking about data storing. We use SSD as boot devices because THEY ARE FAST thanks to their flash-nand technologies. HDD can't compete because they use a technology based on cylinders and sectors that are read by a mechanical arm.

Every SSD sold comes with an assurance of I/O operations called TBW: for example my KINGSTON A400 120GB SSD has an assurance of 40TB of writable data!
That's a lot but when you exceeds that number you can except problems comings soon.

A 480GB SSD has a 160TB assurance!

Regarding running OS from RAM... you are right, when the OS preload ALL the data on RAM and then an unexcepted shutdown happens all the data will be lost. But you can also configure your distro you preload on RAM only system & applications file meanwhile your data partition is simply mounted and accessible from your USB.

The assurance for the I/O operations doesn’t seem promising at all! Specially considering that there’s no proper way of measuring how far you’ve reached in your “quota”. And judging by how expensive SSDs are, it doesn’t sound very economic to constantly replace your SSD and go through the hassle of migrating the data to your new one just because you’ve exceeded the assured I/O operations.