Upload & Sell: Off
Samsung HDD part was bought by Seagate December 2011. Samsung wasnt doing exactly great and Seagate wanted mainly SSD part of business for their own hybrids and SSD. So probably no need to worry about regular HDDs.
How those hybrids work in real life, no idea.. never saw even one. My system consists of SSD for OS and regular HDDs for data. Tho as you said, in theory that SSHD tech could work really good in 2.5" portables. But it will probably end as just temporary (1-3 years) solution, until SSDs will be big enough and whats most important, cheap enough.
3 years of uptime is certainly a lot. And when its in server use then its usually really working, not like in my PC where its nearly 24/7 powered on, but doing pretty much nothing most of the time.