Got some question that i would love some answer.
What’s the most cost and performance efficient device that can run nextcloud? Right now I have raspi 2b, surface pro 4, nvidia shield k1 tablet.
What are the OS that nextcloud support?
are the enterprise feature like contact or calendar in the free personal version?
is there a installation guide in the main site?
The pi is definitely the most efficient in your list, probably on the market too (unless a competing single board pc is drastically cheaper) and forms the basis of the nextcloud box, so more than up to the task.
Server: Linux (Debian 7, SUSE Linux Enterprise Server 11 SP3 & 12, Red Hat Enterprise Linux/CentOS 6.5 and 7 (7 is 64-bit only), Ubuntu 14.04 LTS, 16.04 LTS)