The E3D V5 and V6 are great hot ends! http://e3d-online.com/E3D-v6
One thing to be aware of when switching from a V5 to the V6 is that because of the much more pared down nozzle profile, the force needed for extrusion is lower, this also makes the liquid plastic inside the melt zone much more likely to ooze out under the weight of gravity 😉
This can be an issue or not… For a multi-extrusion setup ooze is a big deal because the extruder not being used will deposit plastic bits all over your print.
For a single extruder most of the difference can be compensated for by increasing the retract distance from .8mm to 1.6mm which seems to get rid of the blob problem.
As you can see from the below image, the amount of ooze from the V6 is over twice the volume of the V5. This is over 30 seconds under identical conditions, I started by first extruding 20mm of filament, then starting a timer when the extrusion stopped and measuring the length of the plastic string that formed from the ooze.