I would like to upgrade my actual NAS (ds215j) to 218play or 218+.
The main reason for this choice is that using plex from my ipad o iphone (sometimes also from my chromecast / Amazon key) get stucked saying “the server is not powerful enough to convert video”.
Obviously if there is a solution, I will be glad to ear it. 
What do you suggest? Actually I use the NAS just to store personal file and to use PLEX.
Thx in advance!