If you use your old ext. HDs as in frequent in/out use of storage it may succumb to the same hassles of failure. If on the other hand, you simply store data it may work out OK. Also, if older HDs were handled wrongly or got roughed-up then that too is why older HD tend to fail. While SSD may provide use in that situation, look-up the "TRIM cmd." to see why SSD can fail. Also, the same proper handling and placement of ext. HD still apply. review all the horror stories and see why externals fail by the cat(pets), kids, falls, storms or long use even.