ASK NC

I own 4 Drobos, the 5 bay FS, 8 bay Drobo pro, 5D and S connected to my Mac laptops (wifi) and Mac Pros directly (networked and 1 running Plex). With so much data across 4 devices, it is difficult to choose the right system that has the feature of beyond raid. I am leaning towards Synology DS1821+ but am not sure where to jump in. Whatever box is chosen, it will start with all new 8tb drives and the old reds will find a home someplace on eBay. Mmoving from Drobo to something else is really important right now and would love advice.

Yes, considering plus series models such as DS1821+ is the right thing to do.
Similar to drop, you will be able to mix different drive sizes.
Migration might take same time because you will need to copy all data over.
But once it is done, you are good to go. Also having 10gbe upgrade feature is handy.

I hope this helps.