Your b+ psu is likely not powerful enough for a 3.
On my network, the 3’s WiFi is useless for DVD.iso… But the V4K’s plays DVD.iso flawlessly In the same location.
The V4K’s gui navigation, movie skipping/fast forward, etc is much faster than a 3… It is worth ditching a 3 for a V4K as the user experience is very very good.
Vero4K Review