Oh, Almighty1 (I just HAD to say that): With the number of write cycles on a SSD being limited, I'd think them a poor choice for use as a "sort of" DVR.
That was my concern as well but it appears that even spinners as the traditional HD's are call still have limited load/unload cycles which is 300,000 if you actually read the spec sheets for hard drives and many drives in my experience can fail anytime before that happens. Read this and you will see that a hard drive can have 43,000 load/unload cycles in just 327 hours alone:
http://wp.xin.at/archives/1221
Even the current Western Digital Black Label 3.5" drives has a lifetime of 300,000 cycles. I consider Western Digital more reliable than Seagate drives as even the firmware on Seagate aka Shugart Technology is not reliable. The only reason they are even good is because they bought CDC (Control Data Corporation)/Imprimis which made the best drives on the market and where the Barracuda drives originated from.
See the spec sheet yourself:
http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-771434.pdf
Only Hitachi Global Storage Technology which was IBMs storage division has 1,000,000 unload/load cycles but ask all the people with DeskStars who had DeathStars that had their drives died without warning in the last 20 years.
https://en.wikipedia.org/wiki/HGST_Deskstar
The drive I have the Samsung Pro 850 SSD has the following specs:
Lifespan with 20GiB of Host Writes per Day with 1.5x Write Amplification 282.74 years
Lifespan with 100GiB of Host Writes per Day with 3x Write Amplification 56.55 years
http://www.anandtech.com/show/8239/update-on-samsung-850-pro-endurance-vnand-die-size
and it comes with a ten year warranty as well plus it's not subject to shocks and vibration or mechanical failure.
MicroSD cards on the other hard is way more risky as I have a SanDisk 200GB MicroSD which is the largest capacity available and the only model available, the card stopped allowing writing after 1.5 months but that's due to the size of the item and they can't put in all the things to make it more reliable. There are always trade offs in all scenarios and this is only a external HDD so unless you use it for buffering, you usually will not have a problem since the 92% capacity of my Hopper 1 for example, the stuff is just things recorded since the last 5 years that I have not watched yet. Once I watch it, it will be archived or deleted.
I deal with 5,000+ servers daily with a 99.6% reliability rate for the last 22 years as I own and run a Internet Service provider so I would know what's reliable and what's not. All you have to do to kill your hard drive or the one in the hopper is while it is on, keep it vertical and let it fall on the hard surface floors, it will kill it immediately as I had done before with a Comcast Motorola/General Instruments DVR accidentally one time. I forgot to mention in 1997, I was the one who ran the home network remotely which had servers running Unix at the home of the founders of Concentric Network Corporation which is now XO Communications and one of the servers was running a Seagate ST41800UW which was basically a 5.25" Full Height 8GB Ultra-Wide SCSI Hard Drive that shook the entire case when it was used. One time someone hacked the system and the next thing we know 30 minutes later, he wrote some software that made the HD spin backwards and kill the drive. Even Seagate was unable to fix it and neither were the Data Recovery companies like Ontrack, DriveSavers, etc.
In the last 7 years I had SSD's, SDCard and MicroSD cards which is in the hundreds, only the one I mentioned had failed and it still allows reading the data, it just doesn't allow formating, erasing or
writing. Yet every hard drive I have bought and used since 1985 which is also in the hundreds other than the 2 x Western Digital 2.5" 750GB 7200rpm Black Label drive has failed atleast once with warranty replacements.
See this review as well:
http://www.pcmag.com/article2/0,2817,2404258,00.asp
"As far as longevity goes, while it is true that SSDs wear out over time (each cell in a flash memory bank has a limited number of times it can be written and erased), thanks to TRIM command technology built into SSDs that dynamically optimizes these read/write cycles, you're more likely to discard the system for obsolescence before you start running into read/write errors. The possible exceptions are high-end multimedia users like video editors who read and write data constantly, but those users will need the larger capacities of hard drives anyway. Hard drives will eventually wear out from constant use as well, since they use physical recording methods. Longevity is a wash when it's separated from travel and ruggedness concerns."