BlackHole and VTi both based on offical Vu+ coding.

Vix, Openpli, and all other images for vu+ box's are all based on Openpli coding.

All images have different tweaks, extra's, layouts to make them all different from each other.

Picture quality and stability should be pretty much the same from all of them.

Functionality and userfriendly is a user preference, and whichever makes you feel more comfortable.

Best bet, try them all and decide for yourself.