Wait until the Odroid N2 comes out. 2 SATA ports and I like the fact all cables will exit the same side if they keep it similar to the N1.
Just be careful with any ARM processor that has the big little CPUS as there was/is an issue with java VM when the java threads switched between the cores and this caused Openhab to crash. Not sure if this is sorted or if it requires you to still implement a work around to pin the java threads to the big cores. You will find details on this both in this forum and in the odroid forum with a fix outlined in the odroid magazine. If you have a XU4 and openhab please post if this is fixed in a newer kernal/java update.
The C2 does not have the big little cores and this coupled with the fact the Odroid C2 is an excellent kodi device is why I settled for the “older” C2 with the plan to update to the N2 after it is released and is proven. I then move the C2 to kodi tasks.
I wrote this script to get Openhab running on my C2, but it should work with the other Odroid images as well, just note the big little patch mentioned above.
Short answer is it depends on the device. Emmc and sd are best thought of as the same. It is interesting to know that even in uSD cards there is a very tiny ARM processor that handles wear levelling and other features. There are hacks to turn a uSD card into a MP3 player by reprogramming the arm processor inside the card, pretty cool but getting off topic… The main difference is that emmc MUST implement wear levelling as the standard specifies that it must, with uSD the standard does not specify it has to include wear levelling BUT any decent uSD card will do some kind of wear levelling especially if it is 32gb or more in size.
As for reserving power and watching for power issues to then close open BLOCKS back to the flash it depends on the device and it could easily be done with SD cards or any flash device as well. At the end of the day a raspberry Pix (and other clones) are designed to be sold at $35 and hence they make hardware choices to bring out a fantastic product at that price point. Why make the hardware cost more when 98% of users don’t need the feature, or there is another way to achieve the same result? You can add on a UPS that shuts down the PI pretty easily, the same for the odroid range. You can also do software work arounds.
This UPS is designed for the C2 and it is marketed and I quote
*** “It will significantly reduce the risk of data loss by sudden power-down.” ***
https://www.hardkernel.com/main/products/prdt_info.php?g_code=G146068525665
Lastly to give a different view on the topic of how to backup, this how to may be of interest…