You ask if the nexus will be too slow, yet you're coming from an iPad mini...
Of course they will run great! I've tried NES, SNES, GBA, DS, and have heard a out PSX and PSP emulators running flawlessly.
Sent from my Nexus 7 using Tapatalk HD
Phone: Samsung Galaxy S3 I747M
Tablet: Nexus 7 (2013)