Medpore implants are among the best tolerated implants because their porous nature allows your blood vessels to grow into the implant and make it more like a part of your body. This makes them less apt to move than silicone elastomers which become surrounded by scar tissue but are not fixated to the underlying structures.
Another item the goes in your favor is that Asian skin IS thicker than Caucasian skin and is generally better able to tolerate an underlying implant. As a result, it is common in the Far East for surgeons to augment the classic low dorsum Asian nose with a silicone L shaped implant AND for it to last a long time in many cases. (This is usually not possible in most western noses where the implants quickly erode through the nose skin and become exposed and infected).
That being said - we are all different and have different - yet to be discovered karmas and futures. There is NO WAY to predict, much less, guarantee that your Porex nose implant would last 5 months or 50 years.
I agree with my colleagues, Drs. Placik and Rand, that if you wanted to stack longevity and durability, your graft should come from YOUR body.