Originally Posted by Hoathy
Obviously to operate it requires that I'm in the Nether so as to cause the Blazes to spawn. This means it shouldn't be a drain on the server at all and would be a good way to farm blazes rods (which have a number of uses).
It doesn't require you to be in the Nether. I was under the impression that any Nether portal that is active in the Overworld also has its chunk active in the Nether. This way, anything in the Nether world can walk through to the Overworld, e.g. pigmen. Therefore, by simply having a two-way portal (rather than the Myst one-way gates), you add to the load of the server as it has to maintain chunks on either side of the portal.
On Frontier, this isn't true simply because Bukkit has got around this Nether/Overworld travel problem by deactivating it.
Mystcraft gates might not have the same issue. I don't know.
Personally, I would rather see players get creative with how to kill blazes in the Nether, rather than transport them between worlds to kill them.