I bought sandisk 16gb pendrive 5 years ago. It has a plastic body and still is in a good working condition. It's 3.0 & gives an average data transfer speed around 40mbps.
It is a really good product for general use. If maintained properly, it can be used for many years.
People frequently complain about the plastic body breaking or sometimes get access errors.
This is completely their fault. Not the product fault. Sometimes the usb ports r so tight that people try to push the pendrive in anyhow. This causes damage to the external plastic body of the pendrive. Please dont do this. Handle the pendrive gently.
Also, donot remove ur pendrive while in use without ejecting first. This might create access errors next time u try to use ur pendrive.