No brainer on this one. Go new as you would probably get another couple of years of cloud support on the new EX2 ultra.
This way, once you get the new EX2 Ultra it is the safest to just copy the data over and keep the old EX2 for backup.
Although the EX2 has the feature to upgrade your hard drive size by inserting a larger drive on the opposing mirror, DON’T DO IT! as seriously it puts your data to risk since whomever wrote that piece of software is not a NAS server developer. None of your data is protected as I tried recently on upgrading a test 2TB disk to an exactly the same size 2TB disk and it failed because I did not supply a large disk and all data was lost. Although there is a possibility that it would succeeded if I had a larger drive, as probably millions has used the utility, unless you have a backup, upgrading the drives with your only copy of data is not worth the test.
Thus the safest, quickest and easiest method of upgrading any hardware is to copy from one device to another.
The new EX2 ultra does support up to 10TB per disk (tested) and perhaps more but unknown at this time because once you support the drive barrier of 10TB, going up to 16TB per drive should be no problem.
You can choose to buy the diskless model and add the disks separately giving you, I believe, 5 years of warrantly on bare drives versus 2 years if you buy them together (definitely just a customer spouting numbers off the top of his head). Although which ever is cheapest is probably the best route to pursue.
Of course in addition to supporting larger disks, the CPU/Memory is improved giving you quicker access although in reality it is like comparing two mobile phones that really doesn’t show how much faster one is over the other; so spec wise it just feels better.
I do get 100MB/s read/writes on my EX2 Ultra through a gigabit network versus the old 70MB/s read/writes on my old Single Bay 4TB My Cloud drives which is similar to your EX2 in build in 2015. This is the maximum speed on a large movie file so in general use you really won’t notice the speed difference as copying a 1GB file to and from any My Cloud drive takes roughly 8 to 10 seconds anyways. Copying MP3’s, photos and large quantity of small files always reduces any file server down to about 2 to 7 MB/s due to the nature of small file copying.
None of the apps are worth talking about as most of them are trials. The rest you shouldn’t use like bittorrent on a My Cloud that takes a whole week to download a file versus 5 to 10 minutes on your PC.
Although PLEX support on your new EX2 Ultra is very nice to have as it turns your EX2 into a true blue movie server. The only problem is that now your device is opened to the internet, you cannot help but feel like you have added yourself into a bittorrent movie stream to the world as your EX2 chatters all through the night as though someone is watching your movie files.
Anyways, when choosing to upgrade disks or upgrading to a newer product, always choose the newer product unless it is the new My Cloud Home of which you should avoid at all costs.
