I need durable outdoor objects, and I use all different materials, most of them are printed at 250-280°C, which original UM2 hotend can handle but only for short time before PTFE burns out. If UM2 could handle 24/7 printing @280°C I would have no need for other heat end.
I have zero issue with E3D V6 and PLA, it prints perfectly! I had prints for over 30 hours without any problems. What kind of issues did you have? Did you use original E3D head or cheap knock-offs ?